Решите уровнения (1 - 7/10) x = 2 1/4 (3 1/8 + 1 3/4) x = 2 1/6 (1/4+1/5) x = 1 4/5 (2 1/12 - 1 5/6) x = 3//4

(1 - 7/10) * x = 2 1/4;

(10/10 - 7/10) * х = 9/4;

3/10 * х = 9/4;

х = 9/4 : 3/10;

х = 9/4 * 10/3;

х = 90/12;

х = 15/2.

Проверка:

(1 - 7/10) * 15/2 = 2 1/4;

(10/10 - 7/10) * 15/2 = 9/4;

3/10 * 15/2 = 9/4;

45/20 = 9/4;

9/4 = 9/4. Решение верно.

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

(25/8 + 7/4) * х = 13/6;

(25/8 + 14/8) * х = 13/6;

39/8 * х = 13/6;

х = 13/6 : 39/8;

х = 13/6 * 8/39;

х = (13 * 8) / (6 * 39);

х = 104/234;

х = 52/117.

х = 4/9.

Проверка:

(3 1/8 + 1 3/4) * 4/9 = 2 1/6;

(25/8 + 7/4) * 4/9 = 13/6;

(25/8 + 14/8) * 4/9 = 13/6;

39/8 * 4/9 = 13/6;

(39 * 4) / (8 * 9) = 13/6;

156/72 = 13/6;

13/6 = 13/6. Решение верно.

(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 = 180/45;

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.

(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.

(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;

9/12 = 3/4;

3/4 = 3/4. Решение верно.