一道数学题 急急急急

1/2*(4)=1/中袭2*(1/2-1/御皮4)
1/4*(6)=1/2*(1/4-1/6)
后面以此类推
所以镇培差
1/2*(4)+1/4*(6)+1/6*(8)+·······1/2008*(2010)
=1/2*(1/2-1/4+1/4-1/6+1/6-1/8+·······1/2008-1/2010)
=1/2*(1/2-1/2010)
=251/1005

=1/2*(2+2)+1/4(4+2)..........1/2008(2008+2)
=1+1+1+1/2+1+1/棚粗咐3+.............1/2008+1/链纯1004
=1004+1005/1004*502
=1004+1005/凳森2

1/档伍2*(4)+1/4*(6)+1/行配或6*(8)+·······1/卖扰2008*(2010)
=2/1+3/2+4/3+……+1005/1004
=1004+(1+1/2+1/3+1/4+……+1/1004）

1/2*(4)+1/4*(6)+1/6*(8)+·······1/2008*(2010)
=2/1+3/2+4/洞握巧3+……皮腊+1004/纳键1003
=1003