Sizing Them Up: For each of Problems 1 and 2 determine the dimension and find a basis for the subspace W of the vector space V?
1. V = R3; W = {[x1, x2, x3] | x1 + x2 + x3 = 0}
2. V = R4; W = {[x1, x2, x3, x4] | x1, + x3 = 0, x2 = x4}