help direct variation

Question

I have 3 questions are

y=- 2x

y= - 2x+3

y= -3/2x

direct variations?

Answer 1

A direct variation has the form:

y = kx

where k is a constant. Let's see if each of the three equations fits the model:

1. y = -2x fits the model y = kx when k = -2. So yes, it's a direct variation
2. y = -2x + 3. The -2x parts fits but the + 3 part does not. So no, it's not a direct variation
3. y = (-3/2)x fits the model y = kx for k = -3/2.