Pleaseee help me out reall quick

Which function has an inverse function? a.f(x)= |x+3|/5 b. f(x)= x^5-3 c. f(x)= x^4/7+27 d. f(x)= 1/x²

Write an inequality for this description. - one fourth of the opposite of the difference of five and a number is less than twenty.

Write as a product: ac^2–ad+c^3–cd–bc^2+bd