计算极限lim(lim下面是x→2)x^2-4/x^2-6x+8

Question

计算极限lim(lim下面是x→2)x^2-4/x^2-6x+8

Answer 1

lim(lim下面是x→2)x^2-4/x^2-6x+8=lim(lim下面是x→2)(x-2)(x+2)/x-2)(x-4)
lim(lim下面是x→2)(x+2)/(x-4)=-2