已知/XY-2/(這是絕對值的符號)與/Y-1/互為相反數. (1)求X,Y的值; (2)求1/(這是分數符號)XY+1/(X+1)(Y+1)+1/(X+2)(Y+2)+…+1/(X+2009)(Y+2009)的值.

已知/XY-2/(這是絕對值的符號)與/Y-1/互為相反數. (1)求X,Y的值; (2)求1/(這是分數符號)XY+1/(X+1)(Y+1)+1/(X+2)(Y+2)+…+1/(X+2009)(Y+2009)的值.

1:絕對值永遠大於等於0|xy-2|+|y-1|=0|xy-2|=0,|y-1|=0xy=2y-1=0y=1,x=22:1/xy+1/(x+1)(y+1)+…+1/(x+2009)(y+2009)=1/2*1+1/3*2+1/4*3+…+1/2011*2010=1-1/2+1/2-1/3+1/3-1/4+…+1/2010-1/2011=1-1/2011=2010/2…