Уравнение (1/4+1/5) x=1 4/5. (3 1/8+1 3/4) x=2 1/6. (2 1/12-1 5/6) x=3/4

(1/4 + 1/5) * x = 1 4/5;

(5/20 + 4/20) * х = 9/5;

9/20 * х = 9/5;

х = 9/5 : 9/20;

х = 9/5 * 20/9;

х = 20/5

х = 4.

Проверка:

(1/4 + 1/5) * 4 = 1 4/5.

(5/20 + 4/20) * 4 = 9/5;

9/20 * 4 = 9/5;

36/20 = 9/5;

9/5 = 9/5. Решение верно.

(3 1/8 + 1 3/4) * x = 2 1/6;

(24/8 + 7/4) * х = 13/6;

(24/8 + 14/8) * х = 13/6;

38/8 * х = 13/6;

х = 13/6 : 38/8;

х = 13/6 * 8/38;

х = 104/228;

х = 26/57.

Проверка:

(3 1/8 + 1 3/4) * 26/57 = 2 1/6;

(24/8 + 7/4) * 26/57 = 13/6;

(24/8 + 14/8) * 26/57 = 13/6;

38/8 * 26/57 = 13/6;

988/456 = 13/6;

13/6 = 13/6. Решение верно.

(2 1/12 - 1 5/6) * x = 3/4;

(25/12 - 11/6) * х = 3/4;

(25/12 - 22/12) * х = 3/4;

3/12 * х = 3/4;

1/4 * х = 3/4;

х = 3/4 : 1/4;

х = 3/4 * 4/1;

х = 12/4;

х = 3.

Проверка:

(2 1/12 - 1 5/6) * 3 = 3/4;

(25/12 - 11/6) * 3 = 3/4;

(25/12 - 22/12) * 3 = 3/4;

3/12 * 3 = 3/4;

1/4 * 3 = 3/4;

3/4 = 3/4. Решение верно.