{"id":94,"date":"2023-06-21T13:22:32","date_gmt":"2023-06-21T13:22:32","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/gsu-collegealgebra\/chapter\/solve-rational-equations\/"},"modified":"2023-07-10T16:13:27","modified_gmt":"2023-07-10T16:13:27","slug":"solve-rational-equations","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/gsu-collegealgebra\/chapter\/solve-rational-equations\/","title":{"raw":"\u25aa   Solving Rational Equations","rendered":"\u25aa   Solving Rational Equations"},"content":{"raw":"<div class=\"textbox learning-objectives\">\r\n<h3>Learning Outcomes<\/h3>\r\n<ul>\r\n \t<li>Solve rational equations by clearing denominators<\/li>\r\n \t<li>Identify extraneous solutions in a rational equation<\/li>\r\n<\/ul>\r\n<\/div>\r\nEquations that contain rational expressions are called <strong>rational equations<\/strong>. For example, [latex] \\frac{2x+1}{4}=\\frac{x}{3}[\/latex] is a rational equation.\u00a0Rational equations can be useful for representing real-life situations and for finding answers to real problems. In particular, they are quite good for describing a variety of\u00a0proportional relationships.\r\n\r\nOne of the most straightforward ways to solve a rational equation is to eliminate denominators with the common denominator and then use properties of equality to isolate the variable. This method is often used to solve linear equations that involve fractions as in the following example:\r\n\r\nSolve \u00a0[latex]\\frac{1}{2}x-3=2-\\frac{3}{4}x[\/latex] by clearing the fractions in the equation first.\r\n\r\nMultiply both sides of the equation by\u00a0[latex]4[\/latex], the common denominator of the fractional coefficients.\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}\\frac{1}{2}x-3=2-\\frac{3}{4}x\\\\ 4\\left(\\frac{1}{2}x-3\\right)=4\\left(2-\\frac{3}{4}x\\right)\\\\\\text{}\\\\\\,\\,\\,\\,4\\left(\\frac{1}{2}x\\right)-4\\left(3\\right)=4\\left(2\\right)+4\\left(-\\frac{3}{4}x\\right)\\\\2x-12=8-3x\\\\\\underline{+3x}\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\underline{+3x}\\\\5x-12=8\\,\\,\\,\\,\\,\\,\\,\\,\\\\\\,\\,\\,\\,\\,\\,\\,\\underline{+12}\\,\\,\\,\\,\\underline{+12} \\\\5x=20\\\\x=4\\end{array}[\/latex]<\/p>\r\nWe could have found a common denominator and worked with fractions, but that often leads to more mistakes. We can apply the same idea to solving rational equations. \u00a0The difference between a linear equation and a rational equation is that rational equations can have polynomials in the numerator and denominator of the fractions. This means that clearing the denominator may sometimes mean multiplying the whole rational equation by a polynomial. In the next example, we will clear the denominators of a rational equation with a term that has a polynomial in the numerator.\r\n<div class=\"bcc-box bcc-info\">\r\n<h3>Example<\/h3>\r\nSolve the equation [latex] \\frac{x+5}{8}=\\frac{7}{4}[\/latex].\r\n[reveal-answer q=\"425621\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"425621\"]\r\n\r\nFind the least common denominator of\u00a0[latex]4[\/latex] and\u00a0[latex]8[\/latex]. Remember, to find the LCD, identify the greatest number of times each factor appears in each factorization. Here,\u00a0[latex]2[\/latex] appears\u00a0[latex]3[\/latex] times, so [latex]2\\cdot2\\cdot2[\/latex], or\u00a0[latex]8[\/latex], will be the LCD.\r\n\r\nMultiply both sides of the equation by the common denominator,\u00a0[latex]8[\/latex], to keep the equation balanced and to eliminate the denominators.\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}8\\cdot \\frac{x+5}{8}=\\frac{7}{4}\\cdot 8\\,\\,\\,\\,\\,\\,\\,\\\\\\\\\\frac{8(x+5)}{8}=\\frac{7(8)}{4}\\,\\,\\,\\,\\,\\,\\\\\\\\\\frac{8}{8}\\cdot (x+5)=\\frac{7(4\\cdot 2)}{4}\\\\\\\\\\frac{8}{8}\\cdot (x+5)=7\\cdot 2\\cdot \\frac{4}{4}\\\\\\\\1\\cdot (x+5)=14\\cdot 1\\,\\,\\,\\end{array}[\/latex]<\/p>\r\nSimplify and solve for <i>x<\/i>.\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}x+5=14\\\\x=9\\,\\,\\,\\end{array}[\/latex]<\/p>\r\nCheck the solution by substituting\u00a0[latex]9[\/latex] for <i>x<\/i> in the original equation.\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}\\frac{x+5}{8}=\\frac{7}{4}\\\\\\\\\\frac{9+5}{8}=\\frac{7}{4}\\\\\\\\\\frac{14}{8}=\\frac{7}{4}\\\\\\\\\\frac{7}{4}=\\frac{7}{4}\\end{array}[\/latex]<\/p>\r\nTherefore, [latex]x=9[\/latex].\r\n\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\nIn the next example, we show how to solve a rational equation with a binomial in the denominator of one term. We will use the common denominator to eliminate the denominators from both fractions. Note that the LCD is the product of both denominators because they do not share any common factors.\r\n<div class=\"bcc-box bcc-info\">\r\n<h3>Example<\/h3>\r\nSolve the equation [latex] \\frac{8}{x+1}=\\frac{4}{3}[\/latex].\r\n\r\n[reveal-answer q=\"331190\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"331190\"]\r\n\r\nClear the denominators by multiplying each side by the common denominator. The common denominator is [latex]3\\left(x+1\\right)[\/latex] since [latex]3\\text{ and }x+1[\/latex] do not have any common factors.\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}3\\left(x+1\\right)\\left(\\frac{8}{x+1}\\right)=3\\left(x+1\\right)\\left(\\frac{4}{3}\\right)\\end{array}[\/latex]<\/p>\r\n<p style=\"text-align: left;\">Simplify common factors.<\/p>\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}3\\cancel{\\left(x+1\\right)}\\left(\\frac{8}{\\cancel{x+1}}\\right)=\\cancel{3}\\left(x+1\\right)\\left(\\frac{4}{\\cancel{3}}\\right)\\\\24=4\\left(x+1\\right)\\\\24=4x+4\\end{array}[\/latex]<\/p>\r\n<p style=\"text-align: left;\">Now this looks like a linear equation, and we can use the addition and multiplication properties of equality to solve it.<\/p>\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}24=4x+4\\\\\\underline{-4}\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\underline{-4}\\\\20=4x\\,\\,\\,\\,\\,\\,\\,\\,\\\\\\\\x=5\\,\\,\\,\\,\\,\\,\\,\\,\\,\\end{array}[\/latex]<\/p>\r\nCheck the solution in the original equation.\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}\\,\\,\\,\\,\\,\\frac{8}{\\left(x+1\\right)}=\\frac{4}{3}\\\\\\\\\\frac{8}{\\left(5+1\\right)}=\\frac{4}{3}\\\\\\\\\\frac{8}{6}=\\frac{4}{3}\\\\\\frac{4}{3}=\\frac{4}{3}\\end{array}[\/latex]<\/p>\r\nTherefore, [latex]x=5[\/latex].\r\n\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<div class=\"bcc-box bcc-info\">\r\n<h3>Example<\/h3>\r\nSolve the equation [latex]\\frac{x}{3}+1=\\frac{4}{3}[\/latex].\r\n\r\n[reveal-answer q=\"950823\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"950823\"]\r\n\r\nBoth fractions in the equation have a denominator of\u00a0[latex]3[\/latex]. Multiply every term on both sides of the equation (not just the fractions!) by\u00a0[latex]3[\/latex].\r\n<p style=\"text-align: center;\">[latex] 3\\left( \\frac{x}{3}+1 \\right)=3\\left( \\frac{4}{3} \\right)[\/latex]<\/p>\r\nApply the distributive property and multiply [latex]3[\/latex] by each term within the parentheses. Then simplify and solve for <i>x<\/i>.\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}3\\left( \\frac{x}{3} \\right)+3\\left( 1 \\right)=3\\left( \\frac{4}{3} \\right)\\\\\\\\\\cancel{3}\\left( \\frac{x}{\\cancel{3}} \\right)+3\\left( 1 \\right)=\\cancel{3}\\left( \\frac{4}{\\cancel{3}} \\right)\\\\\\\\ x+3=4\\\\\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\underline{-3}\\,\\,\\,\\,\\,\\underline{-3}\\\\\\\\x=1\\end{array}[\/latex]<\/p>\r\nTherefore, [latex]x=1[\/latex].\r\n\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\nIn the video that follows, we present two ways to solve rational equations with both integer and variable denominators.\r\n\r\nhttps:\/\/youtu.be\/R9y2D9VFw0I\r\n<h2>Excluded Values and Extraneous Solutions<\/h2>\r\nAs you have seen, some rational expressions have a variable in the denominator. When this is the case, there is an extra step in solving them. Since division by\u00a0[latex]0[\/latex] is undefined, you must exclude values of the variable that would result in a denominator of\u00a0[latex]0[\/latex]. These values are called <strong>excluded values<\/strong>. Let us look at an example.\r\n<div class=\"bcc-box bcc-info\">\r\n<h3>Example<\/h3>\r\nSolve the equation [latex] \\frac{2x-5}{x-5}=\\frac{15}{x-5}[\/latex].\r\n\r\n[reveal-answer q=\"266674\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"266674\"]\r\n\r\nDetermine any values for <i>x <\/i>that would make the denominator\u00a0[latex]0[\/latex].\r\n<p style=\"text-align: center;\">[latex] \\frac{2x-5}{x-5}=\\frac{15}{x-5}[\/latex]<\/p>\r\n\u00a0[latex]5[\/latex] is an excluded value because it makes the denominator [latex]x-5[\/latex] equal to\u00a0[latex]0[\/latex].\r\n\r\nSince the denominator of each expression in the equation is the same, the numerators must be equal. Set the numerators equal to one another and solve for <i>x.<\/i>\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}2x-5=15\\\\2x=20\\\\x=10\\end{array}[\/latex]<\/p>\r\nCheck the solution in the original equation.\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}\\frac{2x-5}{x-5}=\\frac{15}{x-5}\\,\\,\\\\\\\\\\frac{2(10)-5}{10-5}=\\frac{15}{10-5}\\\\\\\\\\frac{20-5}{10-5}=\\frac{15}{10-5}\\\\\\\\\\frac{15}{5}=\\frac{15}{5}\\,\\,\\,\\,\\,\\,\\,\\,\\,\\end{array}[\/latex]<\/p>\r\nTherefore, [latex]x=10[\/latex].\r\n\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\nIn the following video, we present an example of solving a rational equation with variables in the denominator.\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=gGA-dF_aQQQ&amp;feature=youtu.be\r\n\r\nYou have seen that there is more than one way to solve rational equations. Because both of these techniques manipulate and rewrite terms, sometimes they can produce solutions that do not work in the original form of the equation. These types of answers are called <strong>extraneous solutions<\/strong>. That is why it is always important to check all solutions in the original equations\u2014you may find that they yield untrue statements or produce undefined expressions.\r\n<div class=\"bcc-box bcc-info\">\r\n<h3>Example<\/h3>\r\nSolve the equation [latex] \\frac{16}{m+4}=\\frac{{{m}^{2}}}{m+4}[\/latex].\r\n\r\n[reveal-answer q=\"450589\"]Show Solution[\/reveal-answer]\r\n[hidden-answer a=\"450589\"]\r\n\r\nDetermine any values for <i>m <\/i>that would make the denominator\u00a0[latex]0[\/latex]. [latex]\u22124[\/latex] is an excluded value because it makes [latex]m+4[\/latex]\u00a0equal to\u00a0[latex]0[\/latex].\r\n\r\nSince the denominator of each expression in the equation is the same, the numerators must be equal. Set the numerators equal to one another and solve for <i>m.<\/i>\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{l}16=m^{2}\\\\\\,\\,\\,0={{m}^{2}}-16\\\\\\,\\,\\,0=\\left( m+4 \\right)\\left( m-4 \\right)\\end{array}[\/latex]<\/p>\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}0=m+4\\,\\,\\,\\,\\,\\,\\text{or}\\,\\,\\,\\,\\,\\,0=m-4\\\\m=-4\\,\\,\\,\\,\\,\\,\\text{or}\\,\\,\\,\\,\\,\\,m=4\\\\m=4,-4\\end{array}[\/latex]<\/p>\r\nCheck the solutions in the original equation.\r\n\r\nSince [latex]m=\u22124[\/latex] leads to division by\u00a0[latex]0[\/latex], it is an extraneous solution.\r\n\r\nNotice, however, that\u00a0latex]m=4[\/latex] is a solution that results in a true statement.\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}\\frac{16}{m+4}=\\frac{{{m}^{2}}}{m+4}\\\\\\\\\\frac{16}{-4+4}=\\frac{{{(-4)}^{2}}}{-4+4}\\\\\\\\\\frac{16}{0}=\\frac{16}{0}\\end{array}[\/latex]<\/p>\r\n[latex]-4[\/latex] is excluded because\u00a0it leads to division by\u00a0[latex]0[\/latex].\r\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}\\frac{16}{4+4}=\\frac{{{(4)}^{2}}}{4+4}\\\\\\\\\\frac{16}{8}=\\frac{16}{8}\\end{array}[\/latex]<\/p>\r\nTherefore, [latex]m=4[\/latex].\r\n\r\n[\/hidden-answer]\r\n\r\n<\/div>\r\n<h2>Summary<\/h2>\r\nYou can solve rational equations by finding a common denominator. By rewriting the equation so that all terms have the common denominator, you can solve for the variable using just the numerators. Or, you can multiply both sides of the equation by the least common denominator of all fractions so that all terms become polynomials instead of rational expressions.\r\n\r\nAn important step in solving rational equations is to reject any extraneous solutions from the final answer. Extraneous solutions are solutions that do not satisfy the original form of the equation because they produce untrue statements or are excluded values that cause a denominator to equal [latex]0[\/latex].","rendered":"<div class=\"textbox learning-objectives\">\n<h3>Learning Outcomes<\/h3>\n<ul>\n<li>Solve rational equations by clearing denominators<\/li>\n<li>Identify extraneous solutions in a rational equation<\/li>\n<\/ul>\n<\/div>\n<p>Equations that contain rational expressions are called <strong>rational equations<\/strong>. For example, [latex]\\frac{2x+1}{4}=\\frac{x}{3}[\/latex] is a rational equation.\u00a0Rational equations can be useful for representing real-life situations and for finding answers to real problems. In particular, they are quite good for describing a variety of\u00a0proportional relationships.<\/p>\n<p>One of the most straightforward ways to solve a rational equation is to eliminate denominators with the common denominator and then use properties of equality to isolate the variable. This method is often used to solve linear equations that involve fractions as in the following example:<\/p>\n<p>Solve \u00a0[latex]\\frac{1}{2}x-3=2-\\frac{3}{4}x[\/latex] by clearing the fractions in the equation first.<\/p>\n<p>Multiply both sides of the equation by\u00a0[latex]4[\/latex], the common denominator of the fractional coefficients.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}\\frac{1}{2}x-3=2-\\frac{3}{4}x\\\\ 4\\left(\\frac{1}{2}x-3\\right)=4\\left(2-\\frac{3}{4}x\\right)\\\\\\text{}\\\\\\,\\,\\,\\,4\\left(\\frac{1}{2}x\\right)-4\\left(3\\right)=4\\left(2\\right)+4\\left(-\\frac{3}{4}x\\right)\\\\2x-12=8-3x\\\\\\underline{+3x}\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\underline{+3x}\\\\5x-12=8\\,\\,\\,\\,\\,\\,\\,\\,\\\\\\,\\,\\,\\,\\,\\,\\,\\underline{+12}\\,\\,\\,\\,\\underline{+12} \\\\5x=20\\\\x=4\\end{array}[\/latex]<\/p>\n<p>We could have found a common denominator and worked with fractions, but that often leads to more mistakes. We can apply the same idea to solving rational equations. \u00a0The difference between a linear equation and a rational equation is that rational equations can have polynomials in the numerator and denominator of the fractions. This means that clearing the denominator may sometimes mean multiplying the whole rational equation by a polynomial. In the next example, we will clear the denominators of a rational equation with a term that has a polynomial in the numerator.<\/p>\n<div class=\"bcc-box bcc-info\">\n<h3>Example<\/h3>\n<p>Solve the equation [latex]\\frac{x+5}{8}=\\frac{7}{4}[\/latex].<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q425621\">Show Solution<\/span><\/p>\n<div id=\"q425621\" class=\"hidden-answer\" style=\"display: none\">\n<p>Find the least common denominator of\u00a0[latex]4[\/latex] and\u00a0[latex]8[\/latex]. Remember, to find the LCD, identify the greatest number of times each factor appears in each factorization. Here,\u00a0[latex]2[\/latex] appears\u00a0[latex]3[\/latex] times, so [latex]2\\cdot2\\cdot2[\/latex], or\u00a0[latex]8[\/latex], will be the LCD.<\/p>\n<p>Multiply both sides of the equation by the common denominator,\u00a0[latex]8[\/latex], to keep the equation balanced and to eliminate the denominators.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}8\\cdot \\frac{x+5}{8}=\\frac{7}{4}\\cdot 8\\,\\,\\,\\,\\,\\,\\,\\\\\\\\\\frac{8(x+5)}{8}=\\frac{7(8)}{4}\\,\\,\\,\\,\\,\\,\\\\\\\\\\frac{8}{8}\\cdot (x+5)=\\frac{7(4\\cdot 2)}{4}\\\\\\\\\\frac{8}{8}\\cdot (x+5)=7\\cdot 2\\cdot \\frac{4}{4}\\\\\\\\1\\cdot (x+5)=14\\cdot 1\\,\\,\\,\\end{array}[\/latex]<\/p>\n<p>Simplify and solve for <i>x<\/i>.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}x+5=14\\\\x=9\\,\\,\\,\\end{array}[\/latex]<\/p>\n<p>Check the solution by substituting\u00a0[latex]9[\/latex] for <i>x<\/i> in the original equation.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}\\frac{x+5}{8}=\\frac{7}{4}\\\\\\\\\\frac{9+5}{8}=\\frac{7}{4}\\\\\\\\\\frac{14}{8}=\\frac{7}{4}\\\\\\\\\\frac{7}{4}=\\frac{7}{4}\\end{array}[\/latex]<\/p>\n<p>Therefore, [latex]x=9[\/latex].<\/p>\n<\/div>\n<\/div>\n<\/div>\n<p>In the next example, we show how to solve a rational equation with a binomial in the denominator of one term. We will use the common denominator to eliminate the denominators from both fractions. Note that the LCD is the product of both denominators because they do not share any common factors.<\/p>\n<div class=\"bcc-box bcc-info\">\n<h3>Example<\/h3>\n<p>Solve the equation [latex]\\frac{8}{x+1}=\\frac{4}{3}[\/latex].<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q331190\">Show Solution<\/span><\/p>\n<div id=\"q331190\" class=\"hidden-answer\" style=\"display: none\">\n<p>Clear the denominators by multiplying each side by the common denominator. The common denominator is [latex]3\\left(x+1\\right)[\/latex] since [latex]3\\text{ and }x+1[\/latex] do not have any common factors.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}3\\left(x+1\\right)\\left(\\frac{8}{x+1}\\right)=3\\left(x+1\\right)\\left(\\frac{4}{3}\\right)\\end{array}[\/latex]<\/p>\n<p style=\"text-align: left;\">Simplify common factors.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}3\\cancel{\\left(x+1\\right)}\\left(\\frac{8}{\\cancel{x+1}}\\right)=\\cancel{3}\\left(x+1\\right)\\left(\\frac{4}{\\cancel{3}}\\right)\\\\24=4\\left(x+1\\right)\\\\24=4x+4\\end{array}[\/latex]<\/p>\n<p style=\"text-align: left;\">Now this looks like a linear equation, and we can use the addition and multiplication properties of equality to solve it.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}24=4x+4\\\\\\underline{-4}\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\underline{-4}\\\\20=4x\\,\\,\\,\\,\\,\\,\\,\\,\\\\\\\\x=5\\,\\,\\,\\,\\,\\,\\,\\,\\,\\end{array}[\/latex]<\/p>\n<p>Check the solution in the original equation.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}\\,\\,\\,\\,\\,\\frac{8}{\\left(x+1\\right)}=\\frac{4}{3}\\\\\\\\\\frac{8}{\\left(5+1\\right)}=\\frac{4}{3}\\\\\\\\\\frac{8}{6}=\\frac{4}{3}\\\\\\frac{4}{3}=\\frac{4}{3}\\end{array}[\/latex]<\/p>\n<p>Therefore, [latex]x=5[\/latex].<\/p>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"bcc-box bcc-info\">\n<h3>Example<\/h3>\n<p>Solve the equation [latex]\\frac{x}{3}+1=\\frac{4}{3}[\/latex].<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q950823\">Show Solution<\/span><\/p>\n<div id=\"q950823\" class=\"hidden-answer\" style=\"display: none\">\n<p>Both fractions in the equation have a denominator of\u00a0[latex]3[\/latex]. Multiply every term on both sides of the equation (not just the fractions!) by\u00a0[latex]3[\/latex].<\/p>\n<p style=\"text-align: center;\">[latex]3\\left( \\frac{x}{3}+1 \\right)=3\\left( \\frac{4}{3} \\right)[\/latex]<\/p>\n<p>Apply the distributive property and multiply [latex]3[\/latex] by each term within the parentheses. Then simplify and solve for <i>x<\/i>.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}3\\left( \\frac{x}{3} \\right)+3\\left( 1 \\right)=3\\left( \\frac{4}{3} \\right)\\\\\\\\\\cancel{3}\\left( \\frac{x}{\\cancel{3}} \\right)+3\\left( 1 \\right)=\\cancel{3}\\left( \\frac{4}{\\cancel{3}} \\right)\\\\\\\\ x+3=4\\\\\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\,\\underline{-3}\\,\\,\\,\\,\\,\\underline{-3}\\\\\\\\x=1\\end{array}[\/latex]<\/p>\n<p>Therefore, [latex]x=1[\/latex].<\/p>\n<\/div>\n<\/div>\n<\/div>\n<p>In the video that follows, we present two ways to solve rational equations with both integer and variable denominators.<\/p>\n<p><iframe loading=\"lazy\" id=\"oembed-1\" title=\"Solve Basic Rational Equations\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/R9y2D9VFw0I?feature=oembed&#38;rel=0\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<h2>Excluded Values and Extraneous Solutions<\/h2>\n<p>As you have seen, some rational expressions have a variable in the denominator. When this is the case, there is an extra step in solving them. Since division by\u00a0[latex]0[\/latex] is undefined, you must exclude values of the variable that would result in a denominator of\u00a0[latex]0[\/latex]. These values are called <strong>excluded values<\/strong>. Let us look at an example.<\/p>\n<div class=\"bcc-box bcc-info\">\n<h3>Example<\/h3>\n<p>Solve the equation [latex]\\frac{2x-5}{x-5}=\\frac{15}{x-5}[\/latex].<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q266674\">Show Solution<\/span><\/p>\n<div id=\"q266674\" class=\"hidden-answer\" style=\"display: none\">\n<p>Determine any values for <i>x <\/i>that would make the denominator\u00a0[latex]0[\/latex].<\/p>\n<p style=\"text-align: center;\">[latex]\\frac{2x-5}{x-5}=\\frac{15}{x-5}[\/latex]<\/p>\n<p>\u00a0[latex]5[\/latex] is an excluded value because it makes the denominator [latex]x-5[\/latex] equal to\u00a0[latex]0[\/latex].<\/p>\n<p>Since the denominator of each expression in the equation is the same, the numerators must be equal. Set the numerators equal to one another and solve for <i>x.<\/i><\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}2x-5=15\\\\2x=20\\\\x=10\\end{array}[\/latex]<\/p>\n<p>Check the solution in the original equation.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{r}\\frac{2x-5}{x-5}=\\frac{15}{x-5}\\,\\,\\\\\\\\\\frac{2(10)-5}{10-5}=\\frac{15}{10-5}\\\\\\\\\\frac{20-5}{10-5}=\\frac{15}{10-5}\\\\\\\\\\frac{15}{5}=\\frac{15}{5}\\,\\,\\,\\,\\,\\,\\,\\,\\,\\end{array}[\/latex]<\/p>\n<p>Therefore, [latex]x=10[\/latex].<\/p>\n<\/div>\n<\/div>\n<\/div>\n<p>In the following video, we present an example of solving a rational equation with variables in the denominator.<\/p>\n<p><iframe loading=\"lazy\" id=\"oembed-2\" title=\"Solve  Rational Equations with Like Denominators\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/gGA-dF_aQQQ?feature=oembed&#38;rel=0\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>You have seen that there is more than one way to solve rational equations. Because both of these techniques manipulate and rewrite terms, sometimes they can produce solutions that do not work in the original form of the equation. These types of answers are called <strong>extraneous solutions<\/strong>. That is why it is always important to check all solutions in the original equations\u2014you may find that they yield untrue statements or produce undefined expressions.<\/p>\n<div class=\"bcc-box bcc-info\">\n<h3>Example<\/h3>\n<p>Solve the equation [latex]\\frac{16}{m+4}=\\frac{{{m}^{2}}}{m+4}[\/latex].<\/p>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q450589\">Show Solution<\/span><\/p>\n<div id=\"q450589\" class=\"hidden-answer\" style=\"display: none\">\n<p>Determine any values for <i>m <\/i>that would make the denominator\u00a0[latex]0[\/latex]. [latex]\u22124[\/latex] is an excluded value because it makes [latex]m+4[\/latex]\u00a0equal to\u00a0[latex]0[\/latex].<\/p>\n<p>Since the denominator of each expression in the equation is the same, the numerators must be equal. Set the numerators equal to one another and solve for <i>m.<\/i><\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{l}16=m^{2}\\\\\\,\\,\\,0={{m}^{2}}-16\\\\\\,\\,\\,0=\\left( m+4 \\right)\\left( m-4 \\right)\\end{array}[\/latex]<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}0=m+4\\,\\,\\,\\,\\,\\,\\text{or}\\,\\,\\,\\,\\,\\,0=m-4\\\\m=-4\\,\\,\\,\\,\\,\\,\\text{or}\\,\\,\\,\\,\\,\\,m=4\\\\m=4,-4\\end{array}[\/latex]<\/p>\n<p>Check the solutions in the original equation.<\/p>\n<p>Since [latex]m=\u22124[\/latex] leads to division by\u00a0[latex]0[\/latex], it is an extraneous solution.<\/p>\n<p>Notice, however, that\u00a0latex]m=4[\/latex] is a solution that results in a true statement.<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}\\frac{16}{m+4}=\\frac{{{m}^{2}}}{m+4}\\\\\\\\\\frac{16}{-4+4}=\\frac{{{(-4)}^{2}}}{-4+4}\\\\\\\\\\frac{16}{0}=\\frac{16}{0}\\end{array}[\/latex]<\/p>\n<p>[latex]-4[\/latex] is excluded because\u00a0it leads to division by\u00a0[latex]0[\/latex].<\/p>\n<p style=\"text-align: center;\">[latex]\\begin{array}{c}\\frac{16}{4+4}=\\frac{{{(4)}^{2}}}{4+4}\\\\\\\\\\frac{16}{8}=\\frac{16}{8}\\end{array}[\/latex]<\/p>\n<p>Therefore, [latex]m=4[\/latex].<\/p>\n<\/div>\n<\/div>\n<\/div>\n<h2>Summary<\/h2>\n<p>You can solve rational equations by finding a common denominator. By rewriting the equation so that all terms have the common denominator, you can solve for the variable using just the numerators. Or, you can multiply both sides of the equation by the least common denominator of all fractions so that all terms become polynomials instead of rational expressions.<\/p>\n<p>An important step in solving rational equations is to reject any extraneous solutions from the final answer. Extraneous solutions are solutions that do not satisfy the original form of the equation because they produce untrue statements or are excluded values that cause a denominator to equal [latex]0[\/latex].<\/p>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-94\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Original<\/div><ul class=\"citation-list\"><li>Revision and Adaptation. <strong>Provided by<\/strong>: Lumen Learning. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><li>Solve Basic Rational Equations. <strong>Authored by<\/strong>: James Sousa (Mathispower4u.com) for Lumen Learning. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/youtu.be\/R9y2D9VFw0I\">https:\/\/youtu.be\/R9y2D9VFw0I<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><li>Solve Rational Equations with Like Denominators. <strong>Authored by<\/strong>: James Sousa (Mathispower4u.com) for Lumen Learning. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/youtu.be\/gGA-dF_aQQQ\">https:\/\/youtu.be\/gGA-dF_aQQQ<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><li>Solve Basic Rational Equations. <strong>Authored by<\/strong>: James Sousa (Mathispower4u.com) for Lumen Learning. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/youtu.be\/R9y2D9VFw0I\">https:\/\/youtu.be\/R9y2D9VFw0I<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Unit 15: Rational Expressions, from Developmental Math: An Open Program. <strong>Provided by<\/strong>: Monterey Institute of Technology and Education. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><li>Ex 2: Solve a Literal Equation for a Variable. <strong>Authored by<\/strong>: James Sousa (Mathispower4u.com). <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/www.youtube.com\/watch?v=ecEUUbRLDQs&#038;feature=youtu.be\">https:\/\/www.youtube.com\/watch?v=ecEUUbRLDQs&#038;feature=youtu.be<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":395986,"menu_order":21,"template":"","meta":{"_candela_citation":"[{\"type\":\"original\",\"description\":\"Revision and Adaptation\",\"author\":\"\",\"organization\":\"Lumen Learning\",\"url\":\"\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"\"},{\"type\":\"cc\",\"description\":\"Unit 15: Rational Expressions, from Developmental Math: An Open Program\",\"author\":\"\",\"organization\":\"Monterey Institute of Technology and Education\",\"url\":\"\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"\"},{\"type\":\"original\",\"description\":\"Solve Basic Rational Equations\",\"author\":\"James Sousa (Mathispower4u.com) for Lumen Learning\",\"organization\":\"\",\"url\":\"https:\/\/youtu.be\/R9y2D9VFw0I\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"\"},{\"type\":\"cc\",\"description\":\"Ex 2: Solve a Literal 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