Question

Which of the following lines are not parallel to the graph of y = 9x + 1

a. 9y-x=2
b. y-9x=3
c. 9x-y=2
d. 27x-3y=2

Answer 1

A. 9y - x = 2

Explanation:

9y - x = 2. First to get x on the other side we add x to both sides gettings us this. 9y -x + x = 2 + x or just 9y = x + 2. Then divide by 9 to get y alone. We then get y = x/9 + 2/9. The rate of change is clearly not y = 9x here, it's y = x/9 or 1/9x.