Verified answer

Пошаговое объяснение:

(2х + 6)/5 = (5х - 8)/15

15(2х + 6) = 5(5х - 8)

30х + 90 = 25х - 40

30х - 25х = -40 - 90

5х = -130

х = -130 : 5

х = -26

(3 - х)/12 = (-х + 6)/8

12(-х + 6) = 8(3 - х)

-12х + 72 = 24 - 8х

-12х + 8х = 24 - 72

-4х = -48

х = -48 : (-4)

х = 12