Let A be an n×n matrix and let W = {v ∈ Rn|Av = 2v} . Is W a subspace of Rn?

I don't know how to prove it using the subspace test.

I know that W is a subspace of Rn.

I tried saying that the 0 vector is a element of W since v is a element of Rn. Av = 2v

How do you do the addition and scalar multiplication?

Never mind.. I figured it out.