Let a = 1 5-[ ]] d = NO 9.1 Out of a, b, c, d, and e, which vectors are (a) linear combinations of a and b? (b) non-negative linear combinations of a and b? (c) convex linear combinations of a and b? 9.2 If possible, find two vectors u and v so that (a) a and c are non-negative linear combinations of u and v but b is not. (b) a and e are non-negative linear combinations of u and v. (c) a and b are non-negative linear combinations of u and v but d is not. (d) a, c, and d are convex linear combinations of u and v. Otherwise, explain why it's not possible