Question

Determine whether the indicated subset is a subspace of the given Euclidean space R^n - {[x,y,z]}|x,y members of R and z=3x+2} in R^3?

Answer 1

[0,0,0] is not in the set, so it can't be a subspace.

Answer 2

Well, that was quite simple actually...I forgot to even look at that..thanks!