5·cubed squreroot - 27+18

so factor - 27

-27=-1 times 3 times 3 times 3

∛ (-1 times 3 times 3 times 3) = 3 times ∛-1

remember that ∛-1=-1

2 times ∛-1=3 times - 1=-3

now we have

5 times (-3) + 18

5 times - 3=-15

-15+18=3

answer is 3