3(x^2 + 2x + 1) = 2x + 2
3x^2 + 6x + 3 = 2x + 2
3x^2 + 4x + 1 = 0
D = 4^2 - 4 * 3 * 1 = 16 - 12 = 4
√D = √4 = 2
x1 = (-4 + 2) / 6 = -2 / 6 = - 1/3
x2 = (-4 - 2) / 6 = - 6 / 6 = -1
Ответ: -1.
(x + 3)(x - 1) = 2x(x - 2) + 5
...
x^2 - 6x + 8 = 0
D = 6^2 - 4*1*8 = 36 - 32 = 4
√D = √4 = 2
x1 = (6 + 2) / 2 = 8 / 2 = 4
x2 = (6 - 2) / 2 = 4 / 2 = 2
Ответ: 2.