0,8*x+0.95*x+49.7=84.7

0,8 * x + 0.95 * x + 49.7 = 84.7;

Найдем х.

(0,8 * x + 0.95 * x) + 49.7 = 84.7;

Вынесем переменную за скобки.

x * (0.8 + 0.95) + 49.7 = 84.7;

x * 1.75 + 49.7 = 84.7;

1.75 * x + 49.7 = 84.7;

1.75 * x = 84.7 - 49.7;

1.75 * x = 84 - 49;

1.75 * x = 40 - 5;

1.75 * x = 35;

1 3/4 * x = 35;

7/4 * x = 35;

1/4 * x = 5;

x = 4 * 5;

x = 20.