Номер 945 , 5 класс помогите пж

1) 9a + 3a + 8b + 4b = 12a + 12b = 12(a + b) = 12*6 = 72
2) 14c + 5d + 13c + 22d = 27c + 27d = 27(c + d) = 27*4 = 108
3) 7x + 8y + 11y + 12x = 19x + 19y = 19(x + y) = 19*3 = 57