Question

Are the graphs of the lines in the pair parallel? Explain.

y = 4x + 6
–15x + 3y = –45

No, since the slopes are different.

Yes, since the slopes are the same and the y-intercepts are different.

No, since the y-intercepts are different.

Yes, since the slopes are the same and the y-intercepts are the same.

Answer 1

Rewrite in slope-intercept form, y = mx + b, so that you can compare the slopes.

y = 4x + 6 m = 4

- 15x + 3y = - 45
add 15x to each side
3y = 15x - 45
divide both sides by 3
y = 5x - 15 m = 5

No, the slopes are different.