A,B,D

EXERCISE 2.1.2: Find a counterexample Find a counterexample to show that each of the statements is false (a) Every month of the year has 30 or 31 days (b) If n is an integer and n2 is divisible by 4, then n is divisible by 4 (c) For every positive integer x, x32x (d) Every positive integer can be expressed as the sum of the squares of two integers. e) The multiplicative inverse of a real number x, is a real number y such that xy-1.Every real number has a multiplicative inverse