The expression is . \ \

              (Substitute s = 4 and t = 8)

To simplify the expression follow the order of operations: (PEMDAS)

1.     Evaluate the expressions inside Brackets/Parenthesis (P).

2.     Evaluate Powers/Exponents (E).

3.     Multiply and/or Divide in order from left to right (MD).

4.     Add and/or Subtract in order from left to right (AS).

A simple technique for remembering the order of operations is turned into phrase

“Please Excuse My Dear Aunty Sally”

First operation is evaluating the expression parenthesis.

                     (Subtract: ) \ \

Next operation is evaluate powers.

                   (Evaluate power: )

The simplified expression value is 1024.