If A is a 6 times 4 matrix and B is a 4 times 5 matrix, then the product AB has 16 entries. True False For any three matrices A. B. and C the following statement holds: If AB = AC. then B = C. True False Find the big-O order of the following sum: Mark all the answers that satisfy the big-O definition. D(1) D(n) D(n^3) D(n^4) D(n^7) Find the best (i.e., lowest) big-O order for f(n), where f(n) = 1 + 4 + 7 +... (3n + 1). Write a pseudocude of an algorithm that takes a list of n integers a_1, a_2.....a_n and finds the number of integers each greater than five in the list