Question

Can some one please explain this to me I am completely lost

Answer 1

Let's look at each square root and what we can take out.


`2 √(20) =2 √(2*2*5) =4 √(5)`

3 square root 7 can not be simplified, as well as 2 square root 5. But, we can change 4 square root 63.


`4 √(63)=4 √(3*3*7)=12 √(7)`

Now, we have:


`4 √(5)-3 √(7) -2 √(5) +12 √(7)`

We can now complete this problem:


`2 √(5)+9 √(7)`

This is the same as the second answer, so that is the correct choice. Let me know if you need any more help!