1.(+1)+(-2)+(+3)+(-4)+^^^^(省略号)+(+99)+(-100) (请写出过程)2.(1-1/2)+(1/2-1/3)+(1/3-1/4)+^^^^(省略号)+(1/2001-1/2002) (请写出过程)3.1/1*2 + 1/2*3 + 1/3*4 +^^^^(省略号)+1/2001*2002 (请写出过程)

1.(+1)+(-2)+(+3)+(-4)+^^^^(省略号)+(+99)+(-100) (请写出过程)2.(1-1/2)+(1/2-1/3)+(1/3-1/4)+^^^^(省略号)+(1/2001-1/2002) (请写出过程)3.1/1*2 + 1/2*3 + 1/3*4 +^^^^(省略号)+1/2001*2002 (请写出过程)
1.(+1)+(-2)+(+3)+(-4)+^^^^(省略号)+(+99)+(-100) (请写出过程)
2.(1-1/2)+(1/2-1/3)+(1/3-1/4)+^^^^(省略号)+(1/2001-1/2002) (请写出过程)
3.1/1*2 + 1/2*3 + 1/3*4 +^^^^(省略号)+1/2001*2002 (请写出过程)

1.(+1)+(-2)+(+3)+(-4)+^^^^(省略号)+(+99)+(-100) (请写出过程)2.(1-1/2)+(1/2-1/3)+(1/3-1/4)+^^^^(省略号)+(1/2001-1/2002) (请写出过程)3.1/1*2 + 1/2*3 + 1/3*4 +^^^^(省略号)+1/2001*2002 (请写出过程)
1.=(1-2)+(3-4)+.+(99-100)
=(-1)+(-1)+.+(-1)
=-50
2.=1+(-1/2+1/2)+(-1/3+1/3)+.+(-1/2001+1/2001)-1/2002
=1-1/2002=2001/2002
3.楼主没加括号吧?应该是1/(1*2)+1/(2*3)+...如果是,则=(1-1/2)+(1/2-1/3)+(1/3-1/4)+.(1/2001-1/2002)
=1+(-1/2+1/2)+(-1/3+1/3)+.+(-1/2001+1/2001)-1/2002
=1-1/2002=2001/2002

1:将+1和-2一起算，+3和-4一起算，以此类推+99和-100一起算，每两项之和为-1，共50项，所以为50
2：去掉小括号，，整理的1-1/2002=2001/2002
3：原式=（1-1/2）+（1/2-1/3）+（1/3-1/4）+......+（1/2001-1/2002）之后同上题

1. 原式=(1-2)+(3-4)+……+(99-100)=50(-1)=-50
2. 原式=1+(-1/2+1/2)+(-1/3+1/3)+……+(-1/2001+1/2001)-1/2002
=1-1/2002=2001/2002
好累，==