Answer:
Explanation:
Break 18 into its prime factors.
√18 = √2 * 3 * 3
Notice that there are two 3s. When you are taking the square root and there a two factors that are the same, you take 1 and put it in front of the root sign. The other one is discarded. The rule does not apply to the 2 since there is only 1 two.
√18 = 3 √2
So the expression now becomes
3√2 - √2 Take out the common factor of √2
√2 (3 - 1) Notice 1 is left behind.
2√2