А) 6x - 12 = 4x - 8
6x - 4x = -8 + 12
2x = 4
x = 2
б) 2/3x = 18
x = 18 : 2/3
x = 18 × 3/2
x = 24/2
x = 12
в) (2x - 5) - (3x - 7) = 4
2x - 5 - 3x + 7 = 4
-x + 2 = 4
-x = 4 - 2
-x = 2
x = -2
г) 5(x - 1,2) - 3x = 2
5x - 6 - 3x = 2
2x - 6 = 2
2x = 2 + 6
2x = 8
x = 4