2,5 * (x-4/5) / 2/11=2*9/11

Решим уравнение:

2,5 * (х - 4/5) : 2/11 = 2 * 9/11;

2 * 9/11 = (2 * 9) / 11 = 18/11 = 1 (18 - 1 * 11) / 11 = 1 (18 - 11) / 11 = 1 7/11.

2,5 * (х - 4/5) : 2/11 = 1 7/11.

Умножим уравнение на 2/11:

2,5 * (х - 4/5) = 1 7/11 * 2/11.

1 7/11 * 2/11 = 18/11 * 2/11 = (18 * 2) / (11 * 11) = 36/121.

2,5 * (х - 4/5) = 36/121.

Поделим уравнение на 2,5:

х - 4/5 = 36/121 : 2,5;

36/121 : 2,5 = 36/121 : 25/10 = 36/121 * 10/25 = (36 * 5 * 2) / (121 * 5 * 5) = 72/605.

х - 4/5 = 72/605;

х = 72/605 + 4/5;

72/605 + 4/5 = 72/605 + (4 * 121) / 605 = (72 + 484) / 605 = 556/605.

х = 556/605.