7-2(4-х) =-1 -3(х+5)=2х 12-3(х+4)=9 (х+4)-4(х+1)=1

Решаем линейные уравнения используя тождественные преображения.

1) 7 - 2(4 - x) = -1;

7 - (8 - 2x) = -1;

7 - 8 + 2x = -1;

2x = -1 - 7 + 8;

2x = -8 + 8;

2x = 0;

x = 0.

2) -3(x + 5) = 2x;

-3x - 15 = 2x;

-3x - 2x = 15;

x(-3 - 2) = 15;

-5x = 15;

x = 15 : (-5);

x = -3.

3) 12 - 3(x + 4) = 9;

12 - 3x - 12 = 9;

-3x = 9 - 12 + 12;

-3x = 9;

x = 9 : (-3);

x = -3.

4) (x + 4) - 4(x + 1) = 1;

x + 4 - 4x - 4 = 1;

x - 4x = 1 - 4 + 4;

x(1 - 4) = 1;

-3x = 1;

x = 1 : (-3);

x = -1/3.

Ответ: 1) x = 0; 2) x = -3; 3) x = -3; 4) x = -1/3.