Elementary Algebra

In order to simplify this number, first look for the largest factor of 72 that is a perfect square. This number is 36. Then, multiply this number by two inside of the radical. Next, cancel out the power to get it out of the radical to simplify. The Math can be shown as follows: $$5\sqrt{2\times36} \\ 5 \sqrt{ 2 \times 6^2} \\ 5 \times 6 \sqrt{2} \\30\sqrt{2}$$