1+1⼀2-5⼀6+7⼀12-9⼀20+11⼀30-13⼀42+15⼀56-17⼀72 不通分,如何简便计算

2024-11-17 10:36:55
推荐回答(2个)
回答1:

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

回答2:

1+1/2-5/6+7/12-9/20+11/30-13/42+15/56-17/72
=1+1/2-1/2-1/3+1/3+1/4-1/4-1/5+1/5+1/6-1/6-1/7+1/7+1/8-1/8-1/9
=1-1/9
=8/9