Answer:
Explanation:
I imagine that you are simplifying this, since there is nothing else you can do with it. You are in the section in algebra where you're learning how to simplify radicals. ALWAYS think prime factorization when it comes to numbers. For example, the square root of 5...the prime factorization of 5 is simply 5 * 1. So we know that √5 is as simple as it can be. It would benefit us if we could simplify either of the other 2 radicals down to the same radicand so we could add or subtract them.
The prime factorization of 20 is
20--> 5 * 4
4--> perfect square (2×2). So the simplification of 6√20 is 6×2√5 which is 12√5.
The prime factorization of 45 is
45--> 5 * 9
9--> perfect square (3×3). So the simplification of 5√45 is 5×3√5 which is 15√5.
Put it all together to get
12√5 + 8√5 -15√5 which simplifies to
5√5