1 because using your order of operations you start parenthesis and inside that parenthesis is an exponent so you start with that. So 2^3 is 8. Now you have 20-(3x8-5). Now you do the multiplication in the parenthesis. So you get 20-(24-5). Finishing what is in the parenthesis you subtract 5 from 24 to get 20-19 or 1.
