几道算术题···············要用简便算法1.1/2 +1/6+1/1...

几道算术题···············要用简便算法 1.1/2 +1/6+1/12 +1/20+1/30+1/42 2.0.84+3又1/3+0.2+6又2/3*0.48

第1个回答  2020-04-11
1)
1/2
=
1/1
-
1/2,1/6
=
1/2
-
/3,1/12
=
1/3
-
1/4……所以加减合并之后变成了:(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+(1/6-1/7)
=
1
-
1/7
=
6/7.2)暂无