11 3/14−(2−1 11/35):9/25+4/21 .​

11 3/14 - (2 - 1 11/35) : 9/25 + 4/21 = 9 20/21

1) 2 - 1 11/35 = 1 35/35 - 1 11/35 = 24/35

2) 24/35 : 9/25 = 24/35 · 25/9 = (8·5)/(7·3) = 40/21 = 1 19/21

3) 11 3/14 - 1 19/21 = 11 9/42 - 1 19/42 = 10 51/42 - 1 19/42 = 9 32/42 = 9 16/21

4) 9 16/21 + 4/21 = 9 20/21