(2 1/4 - 1 1/4 *(2/7 + 3 1/7 * 1/3)) : 0,7

(2 1/4 - 1 1/4 · (2/7 + 3 1/7 · 1/3)) : 0,7 = 5/6

1) 3 1/7 · 1/3 = 22/7 · 1/3 = 22/21 = 1 1/21

2) 2/7 + 1 1/21 = 6/21 + 1 1/21 = 1 7/21 = 1 1/3

3) 1 1/4 · 1 1/3 = 5/4 · 4/3 = 5/3 = 1 2/3

4) 2 1/4 - 1 2/3 = 2 3/12 - 1 8/12 = 1 15/12 - 1 8/12 = 7/12

5) 7/12 : 0,7 = 7/12 : 7/10 = 7/12 · 10/7 = 10/12 = 5/6

ответ: 5/6.