Решить уравнения: a) 4x + 4 = -12 б) 7x - 6 = x + 12 в) 2(y + 3) = 21 г) 3(3x - 1) - x = 13.

а) 4x + 4 = -12 4x = -12 - 4 4x = -16 x = -16 / 4 **x = -4** б) 7x - 6 = x + 12 7x - x = 12 + 6 6x = 18 x = 18 / 6 **x = 3** в) 2(y + 3) = 21 2y + 6 = 21 2y = 21 - 6 2y = 15 y = 15 / 2 **y = 7.5** г) 3(3x - 1) - x = 13 9x - 3 - x = 13 8x = 13 + 3 8x = 16 x = 16 / 8 **x = 2**