First do the ones in the parentheses. So, 2x3=6. 26-6=20. 20^2=400. Now you have 27-4x400. 4x400=1600. 27-1600=-1573.

You do order of the operation Which is PEMDAS which means Parenthesis, Expontents, Multiplication, Division, Addition, Substration. The answer is 1573