Solving Multi-Step Equations Using a General Strategy
Learning Outcomes
Identify the steps of a general problem solving strategy for solving linear equations
Use a general problem solving strategy to solve linear equations that require several steps
In this section, we will lay out an overall strategy that can be used to solve any linear equation. We call this the general strategy. Some equations won’t require all the steps to solve, but many will. Simplifying each side of the equation as much as possible first makes the rest of the steps easier.
general strategy for solving linear equations
Simplify each side of the equation as much as possible. Use the Distributive Property to remove any parentheses. Combine like terms.
If there are fractions or decimals in the equation, multiply by the least common denominator to clear them.
Collect all the variable terms to one side of the equation. Use the Addition or Subtraction Property of Equality.
Collect all the constant terms to the other side of the equation. Use the Addition or Subtraction Property of Equality.
Make the coefficient of the variable term to equal to [latex]1[/latex]. Use the Multiplication or Division Property of Equality. State the solution to the equation.
Check the solution. Substitute the solution into the original equation to make sure the result is a true statement.
Example
Solve: [latex]3\left(x+2\right)=18[/latex]
Solution:
[latex]3(x+2)=18[/latex]
Simplify each side of the equation as much as possible.Use the Distributive Property.
[latex]3x+6=18[/latex]
Collect all variable terms on one side of the equation—all [latex]x[/latex] s are already on the left side.
Collect constant terms on the other side of the equation.Subtract [latex]6[/latex] from each side.
Simplify each side of the equation as much as possible by distributing.The only [latex]x[/latex] term is on the left side, so all variable terms are on the left side of the equation.
[latex]-x-5=7[/latex]
Add [latex]5[/latex] to both sides to get all constant terms on the right side of the equation.
Watch the following video to see another example of how to solve an equation that requires distributing a fraction.
In the next video example we show an example of solving an equation that requires distributing a fraction. In this case, you will need to clear fractions after you distribute.
In many applications, we will have to solve equations with decimals. The same general strategy will work for these equations.
The following video provides another example of how to solve an equation that requires distributing a decimal.
Licenses and Attributions
CC licensed content, Original
Solve a Linear Equation with Parentheses and Fractions 4/5(2x+3)=5/2x-3. Authored by: James Sousa (Mathispower4u.com) fro Lumen Learning. Located at: https://youtu.be/-P4KZECxo8Y. License: CC BY: Attribution
CC licensed content, Shared previously
Solve a Linear Equation with Parentheses and a Fraction 2/3(9x-12)=8+2x. Authored by: James Sousa (Mathispower4u.com) for Lumen Learning. Located at: https://youtu.be/1dmEoG7DkN4. License: CC BY: Attribution
Solve a Linear Equation with Parentheses and Decimals 0.35(x-0.6)=0.2(x+1.2). Authored by: James Sousa (Mathispower4u.com) for Lumen Learning. Located at: https://youtu.be/k0K8mat_EaI. License: CC BY: Attribution
Question ID 142578, 142579, 142580, 142581, 142582, 142586, 142587, 142589. Authored by: Lumen Learning. License: CC BY: Attribution. License Terms: IMathAS Community License CC-BY + GPL
Question ID 1818. Authored by: Lawrence Morales. License: CC BY: Attribution. License Terms: IMathAS Community License CC-BY + GPL