=(x²-x-2+2x-4)/(x²-x-2)×(x²-1)/(x+3)
=(x²+x-6)/(x-2)(x+1)×(x+1)(x-1)/(x+3)
=(x+3)(x-2)/(x-2)(x+1)×(x+1)(x-1)/(x+3)
=x-1
当x= √3时
原式=x-1=√3-1