14-(5х-6 1/7)=6/7*(5-12х)

Найдем корешки.

14 - (5 * х - 6 1/7) = 6/7 * (5 12 * х);

Раскроем скобки.

14 5 * x + 6 1/7 = 6/7 * 5 6/7 * 12  * x;

14 5 * x + 43/7 = 30/7 84/7 * x;

Умножим уравнение на 7.

14 * 7 5 * x * 7 + 43/7 * 7 = 30/7 * 7 84/7 * 7 * x;

70 + 28 35 * x + 43 = 30 84 * x;

98 35 * x + 43 = 30 84 * x;

141 35 * x = 30 84 * x;

-35 * x + 84 * x = 30 141;

84 * x 35 * x = -111;

x * (84 35) = -111;

x * 49 = -111;

49 * x = -111;

x = -111/49;

x = -2 13/49.