Distribute or not? suppose you need to compute z = (a + b)(x + y), where a and b are m × n matrices and x and y are n-vectors. (a) what is the approximate flop count if you evaluate z as expressed, i. e., by adding a and b, adding x and y, and then carrying out the matrix-vector multiplication? (b) what is the approximate flop count if you evaluate z as z = ax + ay + bx + by, i. e., with four matrix-vector multiplies and three vector additions? (c) which method requires fewer flops? your answer can depend on m and n. remark. when comparing two computation methods, we usually do not consider a factor of 2 or 3 in flop counts to be significant, but in this exercise you can.