Решите уравнение 4x (3x+5) - 3x (4x-1) = 12+26 x

4 * x * (3 * x + 5) - 3 * x * (4 * x - 1) = 12 + 26 * x;

Раскроем скобки.

4 * 3 * x * x + 4 * 5 * x - 3 * 4 * x * x + 3 * 1 * x = 12 + 26 * x;

12 * x^2 + 20 * x - 12 * x^2 + 3 * x = 12 + 26 * x;

20 * x + 3 * x = 12 + 26 * x;

23 * x = 12 + 26 * x;

26 * x - 23 * x = - 12;

x * (26 - 23) = - 12;

x * 3 = - 12;

3 * x = - 12;

x = - 12/3;

x = - 4.