|let w1 and w2 be subspaces of a vector spaces v. define w1+w2 = {v | v= wi + w2 where wi e wi and w2 e w2} a) prove that w1 + w2 is a subspace of v. b) prove t

|Let W1 and W2 be subspaces of a vector spaces V. Define W1+W2 = {v | v= wi + w2 where wi E Wi and w2 E W2} a) Prove that W1 + W2 is a subspace of V. b) Prove that any subspaces of V that contains both W1 and W2 must also contain W1 +W2. can someone please show me how to do this?