Сложите дроби с решением: 1/27 + 5/18, 5/12 + 2/9, 11/24 + 4/15.

Первый пример. 

1/27 + 5/18 = 1 * 18/27 * 18 + 5 * 27/18 * 27 = 18/486 + 18 + 135/486 = 153/486 = 17 * 9/54 * 9 = 17/54;

Второй пример.

5/12 + 2/9 = 5 * 9/12 * 9 + 2 * 12/9 * 12 = 45/108 + 24/108 = 45 + 24/108 = 69/108 = 23 * 3/36 * 3 = 23/36;

Третий пример.

11/24 + 4/15 = 11 * 15/24 * 15 + 4 * 24/15 * 24 = 165/360 + 96/360 = 165 + 96/360 = 261/360 = 29 * 9/40 * 9 = 29/40.