Simplifying Radical Expressions

In this problem, we need to subtract two radical expressions. Let's start by writing down the given expression.

To subtract these, we first need to simplify each radical to see if they are like terms. Let's look at the square root of twenty-seven first.

We can rewrite twenty-seven as the product of nine and three, where nine is a perfect square.

Similarly, we can rewrite twelve as the product of four and three, because four is a perfect square.

Now, we can take the square root of the perfect squares. The square root of nine is three, and the square root of four is two.