question 48 please

45. We have written binary operations in infix notation, where the operation symbol appears between the two operands, as in A+ B. Evaluation of a complicated arithmetic expression is more efficient when the op. erations are written in postfix notation, where the operation symbol appears after the two operands. in AB+. Many compilers change expressions in a computer program from infix to postfix form. One way to produce an equivalent postfix expression from an infix expression is to write the infix expression with a full set of parentheses, move each operator to replace its corresponding right parenthesis, and then elimi nate all left parentheses. (Parentheses are not required in postfix notation.) Thus, A B +C becomes, when fully parenthesized, ((A + B) + C) and the postfix notation is ABC+. Rewrite each of the following expressions in postfix notation: a. (A + B). (C-D) b.4** B - C D (**denotes exponentiation) C. 4.C + B/C +DB) 46. Evaluate the following postfix expressions (see Exercise 45): a 24.5+ b. 51 + 2/1 - c. 34+ 51 -. 47. Let A = {p.4,7,5) B = fr. 1. v C = {p, 5, 1, w) be subsets of S = (p. q. 7, 3, 1, u, v, w). Find a. BnCb. AUCc. C'd. ABC 48. Let A = {p.4,7,5) B = fr. Iv] C = p. 444 be subsets of S - p.g.r. ... v, w). Find a. B-C b. GUB) CAXB d. (UB)