a) (4347 - 3490) * 31 - 4400 : 275 = (857 * 31) - (4400 / 275) = 26567 - 16 = 26551; b) (72198 + 72186) : (48 + 61 * 27) = (144384) : (48 + 1647) = 144384 / 1695 = 85.2; c) 433159 : 851 - 479987 : 943 + 468000 : 2340 = 509 - 509 + 200 = 200; d) 232 * (336392 : 56 - 3862) + 666 = 232 * (6007 - 3862) + 666 = 232 * 2145 + 666 = 497640 + 666 = 498306.