(a) Express the complex number (5-21) in the form a + bi. (b) Express the below complex number in the form a + bi. 3 - 6i i (5-3i) (c) Consider the following matrix. A= 3 185,-142 1 - - 3i 2-41 21 3 - 3i Let B=A. Find b22 (i.e., find the entry in row 2, column 2 of 4) enter your answer in the form a,b enter your answer in the form a,b if your answer is a + bi, then enter a,b in the answer box