求極限lim(x^2-6x+8)/(x^2+x-6)

求極限lim(x^2-6x+8)/(x^2+x-6)

說明:此題不完整.
應該是“求極限lim(x->2)(x^2-6x+8)/(x^2+x-6)”.
原式=lim(x->2){[(x-2)(x-4)]/[(x-2)(x+3)]}
=lim(x->2)[(x-4)/(x+3)]
=(2-4)/(2+3)
=-2/5