3.5x-2.3x+3.8=4.28

Найдем корень.

3.5 * x - 2.3 * x + 3.8 = 4.28;

Приведем уравнение к виду a * x = b.

3.5 * x - 2.3 * x = 4.28 - 3.8;

Вынесем за скобки х.

х * (3,5 - 2,3) = 4,28 - 3,8;

x * (3 - 2 + 0.5 - 0.3) = 1.28 - 0.8;

x * (1 + 0.2) = 0.4 - 0.08;

x * 1.2 = 0.32;

1.2 * x = 0.32;

12 * x = 3.2;

120 * = 32;

x = 32/120;

x = 16/60;

x = 8/30;

x = 4/15.