Question

выполните действие 1/3-1/7

Answer 1

Решение

1/3 - 1/7 = 1*7/21 - 1*3/21 = 7/21 - 3/21 = 7-3/21=4/21

Answer 2

13 - 17
1*73*7 - 1*33*7
721 - 321
7-321
421