How do you simplify the square root of 40?

$2\sqrt{10}$
Explanation:
$\sqrt{40}$
Write the prime factors for 40.
$\sqrt{2\times 2\times 2\times 5}$
Group the same prime factors into pairs.
$\sqrt{(2\times 2)\times 2\times 5}$
Rewrite $(2\times 2)$ in exponent form.
$\sqrt{2^2\times 2\times 5}$
Apply the rule$\sqrt{x^2}=x$
$\sqrt{2^2}=2$
Simplify,
$2\sqrt{2\times 5}$
Simplify,
$2\sqrt{10}$