Решите уравнение: А) 2х + 7 = 3х - 2(3х - 1); Б) 7 - 4(3х - 1) = 5(1 - 2х); В) 12 - (4 - х) 2 = х(3 - х).
а)
2x + 7 = 3x - 2 (3x - 1)
2x + 7 = 3x - 6x + 2
2x -3x +6x = 2 - 7
5x = -5
x = -1
б)
7 - 4(3х - 1) = 5(1 - 2х)
7 - 12x + 4 = 5 - 10x
-12x +10x = 5 - 7 - 4
-2x = -6
x = 3