Question

1-5/6+7/12-9/20+17/30-13/42+15/56-17/72

简便运算 快速回答 采纳+奖励

Answer 1

1-5/6+7/12-9/20+17/30-13/42+15/56-17/72
=1-5/6+7/12-9/20+(11/30+6/30)-13/42+15/56-17/72
=1-5/6+7/12-9/20+11/30-13/42+15/56-17/72+6/30
=1-((2+3)/(2*3))+(3+4)/(3*4))-(4+5)/(4*5))+。。。-((8+9)/(8*9))+1/5
=1-(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)+1/5
=1-1/2-1/3+1/3+1/4-1/4-1/5+1/5+1/6-1/6-1/7+1/7+1/8-1/8-1/9+1/5
=1-1/2-1/9+1/5
=53/90

Answer 2

1-5/6+7/12-9/20+17/30-13/42+15/56-17/72
=(1-5/6)+(7/12-9/20)+(17/30-13/42)+(15/56-17/72)
=1/6+2/15+9/35+2/63
=595/882
无简便运算