Answer
$\sqrt x$$\times$$\sqrt x$ $\ne$ 9
Work Step by Step
The student simplified $\sqrt 3$$\times$$\sqrt 3$ as 9 instead of $\sqrt 9$ = 3
$\frac{1}{\sqrt 3 -1}$ = $\frac{1}{\sqrt 3 -1}$$\times$$\frac{\sqrt 3 +1}{\sqrt 3 +1}$ = $\frac{\sqrt 3 +1}{3-1}$ = $\frac{\sqrt 3 +1}{2}$
