Выполните действие с дробями (3/28-2/35)+(5/14-4/21) посчитайте ​

(3/28 - 2/35) + (5/14 - 4/21) = 13/60

1) 3/28 - 2/35 = 15/140 - 8/140 = 7/140 = 1/20

2) 5/14 - 4/21 = 15/42 - 8/42 = 7/42 = 1/6

3) 1/20 + 1/6 = 3/60 + 10/60 = 13/60

: 13/60.