If you have 54/4 how does it equal 13.5

Evaluate-27 ^4/3/8 a) - 81/16 b) 81/16 c) 16/81

With number 11 ( show how you got the answer)

Desmond wants to sell his car that he paid $8,000 for 2 years ago. the car depreciated, or decreased in value, at a constant rate each month over a 2-year period. if x represents the monthly depreciation amount, which expression shows how much desmond can sell his car for today? \ 8,000 + 24x 8,000 - 24x 8,000 + 2x 8,000 - 2x