Work: 5β2 + β18
First you must find the largest perfect square in β18:
The perfect square happens to be 9
β18 => 9β2
You must then simplify 9 since it is a perfect square:
9β2 => 3β2
Then you must add both terms together:
5β2 + 3β2 = 8β2
8β2 or 8 square root 2
I hope this helps you!