1加二分之一减六分之五加十二分之一减二十分之九加三十分之十一减四十二分之十三

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2024-11-26 14:37:50
推荐回答(3个)
回答1:

解:1+1/2-5/6+1/12-9/20+11/30-13/42(过程可以简化一点,但这样做简单一些,虽然过程烦锁)
=3/2-5/6+1/12-9/20+11/30-13/42
=9/6-5/6+1/12-9/20+11/30-13/42
=4/6+1/12-9/20+11/30-13/42
=8/12+1/12-9/20+11/30-13/42
=9/12-9/20+11/30-13/42
=3/4-9/20+11/30-13/42
=15/20-9/20+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

回答2:

1+1/2-5/6+1/12-9/20+11/30-13/42=1+(6-10+12)/12+(22-27)/60-13/42=1-5/12-1/12+13/42=1-1/2+13/42=1/2+13/42=34/42=17/21.

回答3:

1+1/2-5/6+1/12-9/20+11/30-13/42
=1+1/2-(1/2+1/3)+(1/3-1/4)-(1/4+1/5)+(1/5+1/6)-(1/6+1/7)
=1-1/4-1/4-1/7
=5/14