Question

Which equation represents a proportional relationship? y=2(x+1) y = 4x + 3 y=−2/x y=32x

Answer 1

a proportional relationship
y = kx
so
answer

y=32x

Answer 2

This is what a proportional relationship would look like.
y = mx 
m stands for the number that we will find out later on.
The answer that is closest to the example would be 
D) y = 32x
So that is your answer.