Решите уравнение. 1) 3 (1,2x-4)=1,2 -0,4x 2) 2,4x-6=-1,2x+19,2 3) 4 (0,7x-4)-3

Найдем переменные.

1) 3 * (1,2 * x - 4) = 1,2 - 0,4 * x; 

Раскроем скобки.

3 * 1.2 * x - 3 * 4 = 1.2 - 0.4 * x;

3.6 * x - 12 = 1.2 - 0.4 * x;

3.6 * x + 0.4 * x = 1.2 + 12;

4 * x = 13.2;

x = 13.2/4;

x = 3.3.

2) 2,4 * x - 6 = -1,2 * x + 19,2; 

2.4 * x + 1.2 * x = 19.2 + 6;

3 * x + 0.6 * x = 20.2 + 5;

3.6 * x = 25.2;

x = 25.2/3.6;

x = 7.

3) 4 * (0,7 * x - 4) - 3 * (-0,2 * x + 6) = 0; 

4 * 0.7 * x - 4 * 4 + 3 * 0.2 * x - 3 * 6 = 0; 

2.8 * x - 16 + 0.6 * x - 18 = 0; 

3.4 * x - 16 - 18 = 0; 

3.4 * x - 34 = 0; 

3.4 * x = 34; 

x = 34/3.4; 

x = 340/34; 

x = 10.