3(2х-5) = 18;
-2(1,2х – 5) +4,5 = 3,6х

Пошаговое объяснение:

3(2х-5) = 18;

6x - 15 = 18

6x = 18+15

6x = 33

x = 33:6

x = 5,5

-2(1,2х – 5) +4,5 = 3,6х – 9

-2,4x + 10 + 4,5 = 3,6x - 9

-2,4x + 14,5 = 3,6x - 9

3,6x + 2,4x = 14,5 + 9

6x = 23,5

x = 23,5 : 6

x = 3 11/12