I need to prove that $\frac{1}{x-3} \to 1$ as $x \to 4$
So I did $\left | \frac{1}{x-3} - 1 \right | = \left | \frac{4 - x}{x-3} \right | = \left | \frac{x-4}{x-3} \right | = \frac{|x-4|}{|x-3|} < K|x-4|$. So I need to pick $| x - 4| < \delta = \frac{\epsilon}{K}$
Now the problem is that I can't bound my $\frac{1}{|x-3|}$