Question

1-六分之五+十二分之七-二十分之九+三十分之十一-四十二分之十三

Answer 1

题目是1 - 5/6 + 7/12 - 9/20 + 11/30 - 13/42 ??
若是这样的话,
原式 = (1 - 5/6 + 7/12) + (-9/20 + 11/30) - 13/42
= (12 - 10 + 7)/12 + (-27 + 22)/60 -13/42
= 9/12 - 1/12 -13/42
= 8/12 - 13/42
= 2/3 - 13/42
= (28 - 13)/42
= 15/42 = 5/14

Answer 2

1-5/6+7/12-9/20+11/30-13/42
= 1-9/20+7/12-10/12+11/30-13/42
= 11/20-3/12+11/30-13/42
= 11/20-1/4+11/30-13/42
= 11/20-5/20+11/30-13/42
= 6/20+11/30-13/42
= 3/10+11/30-13/42
= 9/30+11/30-13/42
= 20/30-13/42
= 2/3-13/42
= 28/42-13/42
= 15/42
= 5/14

Answer 3

二十八分之三