(1994+1992+······+4+2)—(1+3+5+······+1991+1993)=( )
数学题2道(很急····························very,Very 急)
(1)用像······似的······造个句子 (2)用像······一样······造一个句子
关联词 就算······( )······
求(2+5+8······+2000)-(1+4+7······+1999)的值.【简算】
1+2++3+··········+10000=
数学题1*2分之一+2*3分之一+3*4分之一+···············+99*100分之一=( )
根据1+2+3+4+······+n=n(n+1)/2 计算2+4+6+····+200
(9999+9997+···+9001)—(1+3+5+····+999)=?
新高一开学,请教(自我介绍)····················
(1+3+5+···+997+999)—(2+4+6+···+998+1000)
4···············
计算(+1)+(-2)+(+3)+(-4)+······+(-100)+(+101)+(-102)