Answer this for me please! thanks very much <3

Can someone me out here number 4 plz

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

Which of the following is an example of a rational number? a. π b. √ 9 c. √ 8 d. 3.8362319