Определите, равны ли дроби. 15/20 и 18/24, 30/48 и 36/56, 20/35 и 16/28, 56/84 и 82/108

1) Сократим дроби:

15/20 = (5 * 3)/(4 * 5) = 3/4;

18/24 = (6 * 3)/(4 * 6) = 3/4;

Ответ: 15/20 = 18/24.

2) 30/48 = (5 * 6)/(6 * 8) = 5/8 = 35/36;

36/56 = (9 * 4)/(14 * 4) = 9/14 = 36/56;

35 < 36;

Ответ: 30/48 < 36/56.

3) 20/35 = (4 * 5)/(5 * 7) = 4/7;

16/28 = (4 * 4)/(4 * 7) = 4/7;

Ответ: 20/35 = 16/28.

4) 56/84 = (4 * 2 * 7)/(4 * 3 * 7) = 2/3 = 36/54;

82/108 = (2 * 41)/(2 * 2 * 27) = 41/54;

36 < 41;

Ответ: 56/84 < 82/108.