9√33

9√11

8√11

They aren't like terms

0

-3√3m

2√45m

2√3m

15√6

90

540

15√6 + √18

4√5 - 5√2

√20 - √50

4√5 - 5√10

4 - 5√2

10

10 - √2

12 + 7√2

√8

92

4√3 - 16√5

-12√15

92 + 16√15