PEMDAS: P = Parenthesis 2

Here's another one:

20 / ( 13 - 11 )^2

PEMDAS... Do P first... Then, do E... Then, do D

20 / ( 13 - 11 )^2 = 20 / 2^2 = 20 / 4 = 5

TRY IT:

5 + ( 10 + 2 - 8 )^3 / 2

of 4