Is y=-2x proportional

Yes, if you are referring to proportionality in general. No if you are referring to a direct proportionality.

Step-by-step explanation:

y = -2x is negatively proportional so it is not directly proportional because y or one quantity decreases when x or another quantity increases. In a directly proportional relationship, as one quantity increases another quantity must increase at the same rate, in other words both must increase thus be positive. When something is proportional it has a constant ratio, and relation.

Direct proportionality or variation is represented by y ∝ x, where ∝ is the symbol used to represent proportionality.

y = kx where k is the constant of proportionality.

Where k = y/x.