7/6+13/12+21/20+31/30+43/ - 知识问答

7/6+13/12+21/20+31/30+43/42+57/56+73/72+93/92=?

2个回答

7/6+13/12+21/20+31/30+43/42+57/56+73/72+91/90
= 8 + 1/6 + 1/12 + 1/20 + 1/30 + 1/42 + 1/56 + 1/72 + 1/90
= 8 + 1/2 - 1/3 + 1/3 - 1/4 + 1/4 - 1/5 + 1/5 - 1/6 + 1/6 - 1/7 + 1/7 - 1/8 + 1/8 - 1/9 + 1/9 - 1/10
= 8 + 1/2 - 1/10
= 8 + 5/10 - 1/10
= 8.4
是不是这个题?

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