0,4x+(-x-1,8)=-2(0,5x-3) решите

Найдем корень уравнения.

0,4 * x + (-x - 1,8) = -2 * (0,5 * x - 3);

Раскроем скобки.

0.4 * x x 1.8 = -2 * 0.5 * x 2 * (-3);

0.4 * x x 1.8 = -1 * x + 2 * 3;

x * (0.4 1) 1.8 = -x + 6;

x * (-0.6) 1.8 = -x + 6;

-0.6 * x 1.8 = -x + 6;

-0.6 * x + x = 6 + 1.8;

x * (-0.6 + 1) = 7.8;

x * (-0.4) = 7.8; 

-0.4 * x  = 7.8;

x = -7.8/0.4;

x = -78/4;

x = -39/2;

x = -19.5;

Ответ: х = -19,5.