А) 5.7 х+7.2 = 2.1 х - 4.8 Б) (0,4 Х-2) - (1 1/2 х+1) = 2.8+4 хВ) 1.2-4 х=-3 (2 х+0.7) = -2.4

А) 5.7 * х + 7.2 = 2.1 * х - 4.8;

5.7 * x - 2.1 * x = - 4.8 - 7.2;

3.6 * x = - 12;

x = - 12/3.6;

x = - 2/0.6;

x = - 1/0.3;

x = - 1 / (3/10);

x = - 10/3.

5.7 * x + 7.2

Б) (0,4 * x - 2) - (1 1/2 * х + 1) = 2.8 + 4 * х;

Раскроем скобки и приведем подобные значения.

0.4 * x - 2 - 1.5 * x - 1 = 2.8 + 4 * x;

-1.1 * x - 3 = 2.8 + 4 * x;

-1.1 * x - 4 * x = 2.8 + 3;

-5.1 * x = 5.8;

x = - 58/51.

В) 1.2 - 4 * х = - 3;

-4 * x = - 3 - 1.2;

-4 * x = - 4.2;

4 * x = 4.2;

2 * x = 2.1;

x = 2.1/2;

x = 1.05.

Г) (2 * х + 0.7) = - 2.4;

2 * x + 0.7 = - 2.4;

2 * x = - 2.4 - 0.7;

2 * x = - 3.1;

x = - 3.1/2;

x = - 1.55.