Выполните действия. А) (15 5/6 - 9 25/27) - (2/3 5/18) + 7/27 + 13/8 Б) (20 8/15 • 7 1/2 - 54 3/5 + 2/5) : (3 13/21 • 8 2/5 - 29 2/5) - 5/6•1 1/5 + 21/25

Question

Александр Акимов

Математика

6 мая, 18:12

Выполните действия. А) (15 5/6 - 9 25/27) - (2/3 5/18) + 7/27 + 13/8 Б) (20 8/15 • 7 1/2 - 54 3/5 + 2/5) : (3 13/21 • 8 2/5 - 29 2/5) - 5/6•1 1/5 + 21/25

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Вера Крючкова · Answer 1

А) (15 5/6 - 9 25/27) - (2/3 - 5/18) + 7/27 + 13/8 = 7 29/72.

15 5/6 = (15 * 6 + 5) / 6 = 95/6.

9 25/27 = (9 * 27 + 25) / 27 = 268/27.

1. 95/6 - 268/27 = 855/54 - 536/54 = 319/54.

2. 2/3 - 5/18 = 12/18 - 5/18 = 7/18.

3. 319/54 - 7/18 = 319/54 - 21/54 = 298/54 на 2 = 149/27.

4. 149/27 + 7/27 = 156/27 на 3 = 52/9.

5. 52/9 + 13/8 = 416/72 + 117/72 = 533/72 = 7 29/72.

Б) (20 8/15 * 7 1/2 - 54 3/5 + 2/5) / (3 13/21 * 8 2/5 - 29 2/5) - 5/6 * 1 1/5 + 21/25 = 98 21/25.

20 8/15 = (20 * 15 + 8) / 15 = 308/15.

7 1/2 = (7 * 2 + 1) / 2 = 15/2.

54 3/5 = (54 * 5 + 3) / 5 = 273/5.

3 13/21 = (3 * 21 + 13) / 21 = 76/21.

8 2/5 = (8 * 5 + 2) / 5 = 42/5.

29 2/5 = (29 * 5 + 2) / 5 = 147/5.

1 1/5 = (1 * 5 + 1) / 5 = 6/5.

1. 308/15 * 15/2 = (308 * 15) / (15 * 2) = 4620/30 = 154.

2. 273/5 + 2/5 = 275/5 = 55.

3. 154 - 55 = 99.

4. 76/21 * 42/5 = (76 * 42) / (21 * 5) = 3192/105 на 21 = 152/5.

5. 152/5 - 147/5 = 5/5 = 1.

6. 5/6 * 6/5 = (5 * 6) / (6 * 5) = 30/30 = 1.

7. 99 / 1 = 99.

8. 99 - 1 = 98.

9. 98 + 21/25 = 98 21/25.