4x - 1 = x + 5 x^2 - 16x = 6x - 25 7x - 4 = 3x - 8

1. 4x - 1 = x + 5;

4x - x = 1 + 5;

3x = 6;

x = 6/3;

x = 2.

Ответ: 2.

2. x^2 - 16x = 6x - 25;

x^2 - 16x - 6x + 25 = 0;

x^2 - 22x + 25 = 0;

D = 484 - 4 * 25 = 384;

x = (22 + - sqrt384) / 2;

x1 = (22 + sqrt384) / 2;

x2 = (22 - sqrt384) / 2.

Ответ: (22 + sqrt384) / 2, (22 - sqrt384) / 2.

3. 7x - 4 = 3x - 8;

7x - 3x = 4 - 8;

4x = - 4;

x = - 4/4;

x = - 1.

Ответ: - 1.