Answer
$\lim\limits_{y \to 4}\frac{4-y}{2-\sqrt y}$ = 4
Work Step by Step
(2 - $\sqrt y$)(2 + $\sqrt y$) = 4 - y. So:
$\frac{4-y}{2-\sqrt y}$$\times$$\frac{2+\sqrt y}{2+\sqrt y}$ = $\frac{(4-y)(2+\sqrt y)}{4-y}$ = 2 + $\sqrt y$. Now we have:
$\lim\limits_{y \to 4}\frac{4-y}{2-\sqrt y}$ = $\lim\limits_{y \to 4}2 + \sqrt y$ = 2 + $\sqrt 4$ = 4
