Answer the following questions. Upload your solutions as a pdf. You must show all necessary work to arrive at your conclusion to receive full credit. 1. True or False. (A B)(A + B) = A? B?. Justify your answer. 1 0 -3 2.letA=12 0 1 . Let B be the reduced row echelon form of A. Write A in the form of U B, where U is 1 1 1 the product of elementary matrices. 3. Prove that if A is invertible and B is row equivalent to A, then B is also invertible