数学题： 求解决： 如果回答得好有追加

1.
97 x 95/96 +47 x 47/48
=(96+1) x 95/96 +(48-1) x 47/48
=96x95/96+95/96+48x47/48-47/48
=95+1-1/96+47-(1-1/48)
=142+1/48-1/96
=142又1/96
2.
1/2 + 1/2x3 + 1/3x4 +……+1/1999x2000
=(1-1/2)+(1/2-1/3)+(1/3-1/4)+...+(1/1999-1/2000) (1/2,1/3等都抵消)
=1-1/2000
=1999/2000
3.
(-1又1/36 + 13/107÷24/107-17/18)÷(-7/8)x1又7/11
=(-1-1/36+13/24-17/18)÷(-7/8)x18/11
=(-1-2/72+39/72-68/72)x(-8/7)x18/11
=(-1-31/72)x(-8/7)x18/11
=103/72*8/7*18/11
=206/77
4.（1-1/2）(1/3-1)(1-1/4)(1/5-1)……(1-1/2010)(1/2011-1)
=1/2 x 2/3 x 3/4 x ...x 2009/2010 x 2010/2011 x (-1)(因为一共有(2011-3)/2+1=1005个奇数,并且奇数对应的为负号)
=-1/2011 (前一个的分母与后一个的分子正好约掉)
5.
1/2002+1/3003+1/4004+1/6006-1/8008
=1/1001（1/2+1/3+1/4+1/6-1/8)
=1/1001 x 9/8
=9/8008
6.A
(2010²-2009²)/(2010²-2009x2011+2x2009）
=(2010²-2009²)/(2010²-(2010-1)x(2010+1)+2x2009）
=(2010+2009)x(2010-2009)/(2010²-（2010²-1）+2x2009）
=(2010+2009)/(2010+2009)
=1
自己验算一下哦