Question

40. The graph of the following system yields perpendicular lines.

x + 2y = -10
-4y = 2x + 20

(True?)

47. The graph of the following system yields parallel lines.

2y = -10 + x
-4y = 2x + 20

(True)

48. The graph of the following system yields parallel lines.

x - 2y = 1
y = -3x + 10

(False)

Are these correct?

Thanks
-MC

Answer 1

47.
2y = -10 + x ----> y = (1/2)x - 5
-4y = 2x + 20 ---> y = (-1/2)x - 5
one slope is 1/2 then other is -1/2, so NOT parallel

your best way is to rewrite in the form
y = mx + b like I did above.

Why are you unsure about the first one ?

Answer 2

Thanks; are the other 2 correct?

-MC