What is th square root of 18?

Answer 1

The square root of 18 is the same as the square root of (9 x 2)

Since 9 is a perfect square, we know the square root of 9 is 3 so you take the 3 and bring it outside the square root sign.

3 x the square root of 2

Some teachers want you to leave it like that but if they want a decimal answer you need to use a calculator. The answer in this situation is 4.24