# How do you simplify 5 sqrt5 times 3 sqrt3?

$15 \sqrt{15}$
$5 \sqrt{5}$ $3 \sqrt{3} = 5 \left(3\right) \sqrt{5} \sqrt{3} = 15 \sqrt{5} \sqrt{3}$
Radicals can be combined if they are the same type (e.g. both square roots): $15 \sqrt{5 \left(3\right)} = 15 \sqrt{15}$