2. Rationalize and simplify the fraction: $\frac{9+2 \sqrt{2}}{4+\sqrt{162}}$
2. It holds that $\frac{9+2 \sqrt{2}}{4+\sqrt{162}}=\frac{9+2 \sqrt{2}}{4+9 \sqrt{2}}=$

$=\frac{9+2 \sqrt{2}}{4+9 \sqrt{2}} \cdot \frac{4-9 \sqrt{2}}{4-9 \sqrt{2}}=$

$=\frac{36-81 \sqrt{2}+8 \sqrt{2}-36}{16-162}=$

$$
=\frac{-73 \sqrt{2}}{-146}=
$$

$$
=\frac{\sqrt{2}}{2}
$$