Simplify Square Root of 18

Here we will show you two methods that you can use to simplify the square root of 18. In other words, we will show you how to find the square root of 18 in its simplest radical form using two different methods.

To be more specific, we have created an illustration below showing what we want to calculate. Our goal is to make "A" outside the radical (√) as large as possible, and "B" inside the radical (√) as small as possible.

√18 = A√B

Greatest Perfect Square Factor Method
The Greatest Perfect Square Factor Method uses the greatest perfect square factor of 18 to simplify the square root of 18. This is how to calculate A and B using this method:

A = Calculate the square root of the greatest perfect square from the list of all factors of 18. The factors of 18 are 1, 2, 3, 6, 9, and 18. Furthermore, the greatest perfect square on this list is 9 and the square root of 9 is 3. Therefore, A equals 3.

B = Calculate 18 divided by the greatest perfect square from the list of all factors of 18. We determined above that the greatest perfect square from the list of all factors of 18 is 9. Furthermore, 18 divided by 9 is 2, therefore B equals 2.

Now we have A and B and can get our answer to 18 in its simplest radical form as follows:

√18 = A√B

√18 = 3√2

Double Prime Factor Method
The Double Prime Factor Method uses the prime factors of 18 to simplify the square root of 18 to its simplest form possible. This is how to calculate A and B using this method:

A = Multiply all the double prime factors (pairs) of 18 and then take the square root of that product. The prime factors that multiply together to make 18 are 2 x 3 x 3. When we strip out the pairs only, we get 3 x 3 = 9 and the square root of 9 is 3. Therefore, A equals 3.

B = Divide 18 by the number (A) squared. 3 squared is 9 and 18 divided by 9 is 2. Therefore, B equals 2.

Once again we have A and B and can get our answer to 18 in its simplest radical form as follows:

√18 = A√B

√18 = 3√2

Simplify Square Root
Please enter another square root in the box below for us to simplify.

Simplify Square Root of 19
Here is the next square root on our list that we have simplifed for you.