a) 623 + (501 - 3 * (9696 / 96)) / 18 = 623 + (501 - 3 * 101) / 18 = 623 + (501 - 303) / 18 = 623 + 198 / 18 = 623 + 11 = 634.
б) 516 + (702 - 4 * (7373 / 73)) * 6 = 516 + (702 - 4 * 101) * 6 = 516 + (702 - 404) * 6 = 516 + 298 * 6 = 516 + 1788 = 2304.