1) 5/48+7/36 = 2) 17/24 - (1/5+5/24) =

1. 5/48 + 7/36 = (5 * 3) / (48 * 3) + (7 * 4) / (36 * 4) = 15/144 + 28/144 = (15 + 28) / 144 = 43/144.

2. 17/24 - (1/5 + 5/24) = 3/10.

1) 1/5 + 5/24 = (1 * 24) / (5 * 24) + (5 * 5) / (24 * 5) = 24/120 + 25/120 = (24 + 25) / 120 = 49/120;

2) 17/24 - 49/120 = (17 * 5) / (24 * 5) - 49/120 = 85/120 - 49/120 = (85 - 49) / 120 = 36/120 = (3 * 12) / (12 * 10) = 3/10.

Решим подобный пример для закрепления материала:

4/32 + 7/48 = (4 * 3) / (32 * 3) + (7 * 2) / (48 * 2) = 12/96 + 14/96 = (12 + 14) / 96 = 26/96 = (2 * 13) / (2 * 48) = 13/48.