Ответ:

2х+ 3(4 - 5х) = 2х + 12 - 15х = 12- 13х

5(9 - 2m) + 10m = 45 - 10m + 10m = 45

-5a + 8(1 + 3a) = -5a + 8 +24a = 8 +19a

-9c - 7(1 - 2c) = -9c - 7 + 14c = 5c - 7