Question

Which equation represents a proportional relationship?

A.y = 5x + 1

B.y=15x

C.y=−x

D.y=−5(x+1)

Answer 1

You know that two variables of an equation are related through direct proportionality when there is a constant value for their ratios. In equation form, a direct proportionality relationship is written as:

y = kx
where k can be any number

Therefore, the answer is B. In this case, k = 15.