42*23 + 17*18 + 24*17 = 23(30+12) + 17(24-18) = 23*30 + 23*12 + 17*24 - 17*18 = (690+276) + (408-306) = 966+102 = 1068
42*23 + 17*18 + 24*17 = 23(30+12) + 17(24-18) = 23*30 + 23*12 + 17*24 - 17*18 = (690+276) + (408-306) = 966+102 = 1068