Which equation represents a proportional relationship?

y=32x

-4xy=8

y+4=x+8

y = 4x + 3

The equation that represents a proportional relationship is:

y = 32x

Because:

y/x = 32

So that implies that y is directly proportional to x.

Note that other equations represent a proportional relationship in some form, only that the relationship y = 32x is the only direct proportional relationship.