Section Exercises

1. When solving an inequality, explain what happened from Step 1 to Step 2:

Step 12x>6Step 2x<3

2. When solving an inequality, we arrive at

x+2<x+32<3

Explain what our solution set is.

3. When writing our solution in interval notation, how do we represent all the real numbers?

4. When solving an inequality, we arrive at

x+2>x+32>3

Explain what our solution set is.

5. Describe how to graph y=|x3|

For the following exercises, solve the inequality. Write your final answer in interval notation.

6. 4x79

7. 3x+27x1

8. 2x+3>x5

9. 4(x+3)2x1

10. 12x54+25x

11. 5(x1)+3>3x44x

12. 3(2x+1)>2(x+4)

13. x+38x+55310

14. x13+x+2535

For the following exercises, solve the inequality involving absolute value. Write your final answer in interval notation.

15. |x+9|6

16. |2x+3|<7 17. |3x1|>11

18. |2x+1|+16

19. |x2|+410

20. |2x+7|13

21. |x7|<4 22. |x20|>1

23. |x34|<2 For the following exercises, describe all the x-values within or including a distance of the given values.

24. Distance of 5 units from the number 7

25. Distance of 3 units from the number 9

26. Distance of 10 units from the number 4

27. Distance of 11 units from the number 1

For the following exercises, solve the compound inequality. Express your answer using inequality signs, and then write your answer using interval notation.

28. 4<3x+218 29. 3x+1>2x5>x7

30. 3y<52y<7+y 31. 2x5<11 or 5x+16 32. [latex]x+7x-axis representing the solution set to the inequality. Show your graph and write your final answer in interval notation.

33. |x1|>2

34. |x+3|5

35. |x+7|4

36. |x2|<7 37. |x2|<0 For the following exercises, graph both straight lines (left-hand side being y1 and right-hand side being y2) on the same axes. Find the point of intersection and solve the inequality by observing where it is true comparing the y-values of the lines.

38. x+3<3x4 39. x2>2x+1

40. x+1>x+4

41. 12x+1>12x5

42. 4x+1<12x+3 For the following exercises, write the set in interval notation. 43. [latex]\{x|-1

52.
Number line with two tick marks labeled: -1 and 2 respectively. There is an open circle around the tick mark labeled -1 and a line that extends leftward from the circle. There is a dot around the tick mark labeled 2 and a line that extends rightward from the dot.

53.
Number line with one tick mark labeled 4. There is a dot on the tick mark and an arrow extending leftward from the dot.

For the following exercises, input the left-hand side of the inequality as a Y1 graph in your graphing utility. Enter y2 = the right-hand side. Entering the absolute value of an expression is found in the MATH menu, Num, 1:abs(. Find the points of intersection, recall (2nd CALC 5:intersection, 1st curve, enter, 2nd curve, enter, guess, enter). Copy a sketch of the graph and shade the x-axis for your solution set to the inequality. Write final answers in interval notation.

54. |x+2|5<2 55. 12|x+2|<4 56. |4x+1|3>2

57. |x4|<3 58. |x+2|5 59. Solve |3x+1|=|2x+3| 60. Solve x2x>12

61. x5x+70, x7

62. p=x2+130x3000 is a profit formula for a small business. Find the set of x-values that will keep this profit positive.

63. In chemistry the volume for a certain gas is given by V=20T, where V is measured in cc and T is temperature in ºC. If the temperature varies between 80ºC and 120ºC, find the set of volume values.

64. A basic cellular package costs $20/mo. for 60 min of calling, with an additional charge of $.30/min beyond that time. The cost formula would be C=$20+.30(x60). If you have to keep your bill lower than $50, what is the maximum calling minutes you can use?