Question

(1/4 + 1/6)•(2/5-1/7)​

Answer 1

1) 1/4 + 1/6 = 3/12 + 2/12.= 5/12

2) 2/5 - 1/7 = 14/35 - 5/35 = 9/35

3) 5/12 * 9/35 = 1/12 * 9/7 = 1/4 * 3/7 = 3/28

Ответ: 3/28