(a) The matrix A can be decomposed using partial pivoting as PA = LU, where U is upper triangular, L is unit lower triangular, and P is a permutation mall-ix. Find the 4 x 4 matrices U, L, and P. (b) IGiven the righthandside vector '1 = (26,9, 1, 3)T, nd )1 that satises Ax = b. {Show your method: do not just guess.)