1+2又6分之1+3又12分之1+4又20分之1+5又30分之1+6又42分之1+7又56分之1+8又72分之1+9又90分之一等于多少

=1+2+3+4+5+6+7+8+9+ 1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
=45+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
=45+1/2-1/10
=45又2/5
有问题，可追问，如满意，请采纳，谢谢！

=1+2+3+4+5+6+7+8+1/6+1/12+1/20+1/30+1/42+1/56+1/72
=36+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
=36+1/2-1/9
=36又7/18

1+2+3+4+5+6+7+8+9+1/6+1/12+1/20+1/30+1/42+1/56
=45+1/2-1/3+1/3-1/4+1/4-1/5+…1/8-1/9+1/9-1/10
=45+1/2-1/10
=44又5分之3

用计算机检查过了，一定正确，望采纳，谢谢！！

原式=1+2+3+...+9+(1/(2*(2+1))+1/(3*(3+1))+...+1/(9*(9+1)))
=1+2+3+...+9+(1/2-1/3+1/3-1/4+...+1/9-1/10)
=45+(1/2-1/10)

=45+2/5

=45.4