=(x-2)/(x+3)(x-3)× (x +2x-3)/(x-2) ×(x+3)/(x+1) =(x-2)/(x+3)(x-3)×(x-3)(x+1)/(x-2) ×(x+3)/(x+1) =1/(x-2) 当x=2010时 原式=1/(2010-2) =1/2008