2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1等于多少
1个回答
你写反了吧
原式=1*2分之1+2*3分之1+……+9*10分之1
=1-1/2+1/2-1/3+……1/9-1/10
=1-1/10
=9/10(10分之9)
相关问题
2\1-6\1-12\1-20\1-30\1-42\1-56\1-72\1-90\1
1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90=
2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1
1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90=?
(1)2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1
计算:1/2+1/6+1/12+1/20+/+1/30+1/42+1/56+1/72+1/90
计算1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
1/12+1/20+1/30+1/42+1/56+1/72+1/90=?
1/12+1/20+1/30+1/42+1/56+1/72+1/90