Sorry I kept thinking the denominator was x-3...So in the case, if I show the 2x^2-18/x+3 =(2x-6) and that the lim_(x->-3) 2x-6=-12 is that all i have to do to show that f is continuous at -3? since the lim as x->-3 of f(x)=f(-3)? Or again do I have to show a proof?