Question

证明limx^2-6x+5/x-5=-4,x趋近于-3

Answer 1

lim{(x²-6x+5)/(x-5)}=(x²-6x+5)/(x-5)=(3²+6*3+5)/(-3-5)=42/(-8)=-4；

或 lim{(x²-6x+5)/(x-5)}=lim{[(x-5)(x-1)]/(x-5)}=lim{(x-1)}=x-1=-3-1=-4；