7. Use elimination by pivoting to find the inverse of the following matri- ces. 2 -3 (a) 1 (b) 2 2 -4 - 1 U -2 3 awN A - I -1 - 3 2 4 -2 (c) 2 (d) 1 -2 -4 4 -2 -1 -3 1 4 2 -3 -1 (e) 2 1 3 (f) 3 -5 -2 5 2 5 6