Simplify Radical Expression

In this problem, we are asked to simplify the radical expression, the square root of one hundred and twenty-eight.

To simplify a square root, we look for the largest perfect square factor of the number under the radical.

Let's test some perfect squares: sixty-four times two equals one hundred and twenty-eight. Since sixty-four is a perfect square, we can use this pair.

We can rewrite the radical as the square root of sixty-four times two.