Exercise 6.2. Prove each of the following statements. (a) There exist integers a and b so that 3a - 46 = 73. (b) There exists an odd integer a and an even integer b so that 3a+4b = 17. (c) There do not exist integers a and b so that 2a + 4b = 25. (d) For every odd integer n 2 3 there exists an odd integer a and an even integer b so that a + b = n