## Textbook Answers – Linear Graphs: Parallel/Perpendicular Lines

July 19, 2016

Workout:

Question 1: (as long as the number in front of the x is the same, you have a correct answer)

(a)  y = 2x + 1       (b) y = 5x – 2      (c)  y = -3x + 4     (d)  y = x + 8

(e)  y = -7x – 5    (f) y = -x + 1      (g)  y = 10x + 9     (h)  y = 5

(i)  y = -x + 1      (j)  y = -2x + 8    (k)  y = 1/2x + 7   (l) y = 3/4x + 1

Question 2:

(a)  y = 3x + 2     (b)   y = 4x + 6     (c)  y = 5x – 3     (d)  y = -2x

(e)  y = -x -4      (f)   y = 1/2x + 5

Question 3:

(a)  y = 5x – 4      (b)  y = -2x + 8     (c)  y = 4x – 5

Question 4:

(a)  y = 2x + 6     (b)  y = 3x – 2     (c)  y = 5x – 1     (d)  y = 3x + 3

(e)  y = 4x + 7     (f)  y = -2x – 6    (g)  y = 6x – 55   (h)  y = -1/2x + 1.5

(i)  y = -x + 4     (j)  y = 1/3x + 1

Question 5:

(a) -1/4     (b)  -3/2     (c)  1/6     (d)  -1/8     (e)  -2     (f)  -1

(g)  3     (h)  5/2     (i)  -7/4     (j)  -2/3      (k)  1      (l)  4/7

Question 6: (as long as the value in front of the x is the same, your answer is correct).

(a)  y = -1/4x + 1     (b)  y = -1/2x + 3     (c)  y = 1/5x – 2     (d)  y = -x + 1

(e) y = x – 1     (f)  y = -2x + 1     (g)  y = -4/3x + 1    (h)  y = 5x – 3

(i)  y = 3/2x + 4    (j)  y = x + 5    (k)  y = -2x – 3    (l)  y = -3/5x + 4

Question 7:

(a)  y = -1/2x + 3    (b)  y = 1/3x – 2   (c)  y = x + 1

(d)  y = -3x       (e)   y = 5x – 2    (f)  y = 9/2x + 6

Question 8:

(a)  y = -x + 4      (b)  y = 1/4x      (c)  y = -1/10x + 9

Question 9:

(a)  y = -1/2x + 2     (b)  y = 1/3x – 1     (c)  y = -1/4x + 2     (d)  y = 2x – 13

(e)  y = -3/2x – 13    (f)  y = 5/3x – 6    (g)  y = 4x + 4

Apply

Question 1:

(a)  y = 3x + 2  and  y = 3x – 2  are parallel

(b) y = 1/2x + 1  and  y = -2x + 3  are perpendicular

(c) y = -2x + 3  goes through the point (0, 3)

(d)  y = 2x  and  y = -5x  pass through the origin

(e)  y = 5x – 4,  y = 3x – 2  and  y = -2x + 3  all pass through the point (1, 1)

Question 2:

No they are not parallel, the gradient of 2x + y = 8 is -2 and the gradient of y=2x+5 is 2.

Question 3:

Yes they are perpendicular.  4x – y – 5 = 0 has a gradient of 4 and the gradient of x + 4y + 1 = 0 is -1/4.

Question 4:

(a)  y = 3x + 4

(b) y = -1/3x + 11

Question 5:

(a)  (-4, 0)

(b)  y = -1/2x – 2

Question 6:

y = 2x + 1

Question 7:

Yes, they are parallel. The gradient of Line L is 1/2 and the gradient of Line N is 1/2.

Question 8:

y = -2/9x – 23/9

Question 9:

a = 5

Question 10:

(a)  y = -2/3x + 12

(b) yes