Jeremy has an $8 gift card to use to buy comic books. Each comic book costs $5.25. The function f(x)=5.25x−8 represents the amount of cash required to purchase x comic books after using his gift card. How much cash does Jeremy need to buy 3 comic books?

A
$7.75

B
$8.25

C
$10.50

D
$15.75

This is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 5 terms.