Решите дроби: г) х-3/7=4/21 д) 4/5-х=1/6 е) 5/8-х=1/3

г) х - 3/7 = 4/21;

х = 3/7 + 4/21;

х = (3 * 3) / (7 * 3) + 4/21;

х = 9/21 + 4/21;

х = 13/21.

Проверка:

13/21 - 3/7 = 4/21;

13/21 - 9/21 = 4/21;

4/21 = 4/21. Решение верно.

д) 4/5 - х = 1/6;

х = 4/5 - 1/6;

х = (4 * 6) / (5 * 6) - (1 * 5) / (6 * 5);

х = 24/30 - 5/30;

х = (24 - 5) / 30;

х = 19/30.

Проверка:

4/5 - 19/30 = 1/6;

24/30 - 19/30 = 1/6;

5/30 = 1/6;

1/6 = 1/6. Решение верно.

е) 5/8 - х = 1/3;

х = 5/8 - 1/3;

х = (5 * 3) / (8 * 3) - (1 * 8) / (8 * 3);

х = 15/24 - 8/24;

х = 7/24.

Проверка:

5/8 - 7/24 = 1/3;

15/24 - 7/24 = 1/3;

9/24 = 1/3;

1/3 = 1/3. Решение верно.