Разберем каждый пример по отдельности:
* 18 + (63 : 9 + 5) * 3 = 18 + (7 + 5) * 3 = 18 + 12 * 3 = 18 + 36 = 54
* (17 + 81 : 9 - 18) + 5 * 7 = (17 + 9 - 18) + 35 = (26 - 18) + 35 = 8 + 35 = 43
* 72 - (54 - 18 * 2) : 9 + 4 = 72 - (54 - 36) : 9 + 4 = 72 - 18 : 9 + 4 = 72 - 2 + 4 = 70 + 4 = 74
* 4 * (56 : 8 + 33 : 11) + 400 = 4 * (7 + 3) + 400 = 4 * 10 + 400 = 40 + 400 = 440