Simplify: sqrt(72) - sqrt(32)

$$
\sqrt{72} = \sqrt{36 \times 2} = 6\sqrt{2}
$$
$$
\sqrt{32} = \sqrt{16 \times 2} = 4\sqrt{2}
$$

$$
6\sqrt{2} - 4\sqrt{2} = (6-4)\sqrt{2} = 2\sqrt{2}
$$
The simplified expression is $\boxed{2\sqrt{2}}$.