## Thinking Mathematically (6th Edition)

$5\sqrt2$
RECALL: For positive real numbers $a$ and $b$, $\sqrt{a} \cdot \sqrt{b} = \sqrt{ab}$ Use the rule above to obtain: $=\sqrt{10(5)} \\=\sqrt{50}$ Factor the radicand so that one of the factors is a perfect square to obtain: $=\sqrt{25(2)} \\=\sqrt{5^2(2)}$ Bring out the square root of the perfect square factor to obtain: $=5\sqrt{2}$