Solutions

Solutions to Try Its

1. x=−5x=−5

2. x=−3x=−3

3. x=103x=103

4. x=1x=1

5. x=−717x=−717. Excluded values are x=−12x=−12 and x=−13x=−13.

6. x=13x=13

7. m=−23m=−23

8. y=4x−3y=4x−3

9. x+3y=2x+3y=2

10. Horizontal line: y=2y=2

11. Parallel lines: equations are written in slope-intercept form.
Coordinate plane with the x-axis ranging from negative 5 to 5 and the y-axis ranging from negative 1 to 6. Two functions are graphed on the same plot: y = x/2 plus 5 and y = x/2 plus 2. The lines do not cross.

12. y=5x+3y=5x+3

Solutions to Odd-Numbered Exercises

1. It means they have the same slope.

3. The exponent of the xx variable is 1. It is called a first-degree equation.

5. If we insert either value into the equation, they make an expression in the equation undefined (zero in the denominator).

7. x=2x=2

9. x=27x=27

11. x=6x=6

13. x=3x=3

15. x=−14x=−14

17. x≠−4x≠−4; x=−3x=−3

19. x≠1x≠1; when we solve this we get x=1x=1, which is excluded, therefore NO solution

21. x≠0x≠0; x=−52x=−52

23. y=−45x+145y=−45x+145

25. y=−34x+2y=−34x+2

27. y=12x+52y=12x+52

29. y=−3x−5y=−3x−5

31. y=7y=7

33. y=−4y=−4

35. 8x+5y=78x+5y=7

37. Parallel
Coordinate plane with the x and y axes ranging from negative 10 to 10. The functions 3 times x minus 2 times y = 5 and 6 times y minus 9 times x = 6 are graphed on the same plot. The lines do not cross.

39. Perpendicular
Coordinate plane with the x and y axes ranging from negative 10 to 10. The function y = negative 3 and the line x = 4 are graphed on the same plot. These lines cross at a 90 degree angle.

41. m=−97m=−97

43. m=32m=32

45. m1=−13, m2=3; Perpendicularm1=−13, m2=3; Perpendicular

47. y=0.245x−45.662y=0.245x−45.662. Answers may vary. ymin=−50, ymax=−40ymin=−50, ymax=−40

49. y=−2.333x+6.667y=−2.333x+6.667. Answers may vary. ymin=−10,ymax=10ymin=−10,ymax=10

51. y=−ABx+CBy=−ABx+CB

53. Yes, they are perpendicular.

The slope for (−1,1) to (0,4) is 3.The slope for (−1,1) to (2,0) is −13.The slope for (2,0) to (3,3) is 3.The slope for (0,4) to (3,3) is −13The slope for (−1,1) to (0,4) is 3.The slope for (−1,1) to (2,0) is −13.The slope for (2,0) to (3,3) is 3.The slope for (0,4) to (3,3) is −13.

55. 30 ft

57. $57.50

59. 220 mi