I need help with this as soon as possible!! Please and thank you!!! ??

The function f(x) = x + 20 is one-to-one. a. Find an equation for f (x), the inverse function. b. Verify that your equation is correct by showing that f (f (x)) =x and f '(f(x)) =x. a. Select the correct choice below and fill in the answer box(es) to complete your choice. (Simplify your answer. Use integers or fractions for any numbers in the expression.) O A. f (x) = , for all x OB. f ( x ) = , for x2 O c. f ( x ) = , forx# OD. f (x) = , forxs b. Verify that the equation is correct. F ( F 1 ( x) ) = () and F 1 ( f ( x ) ) = f ' ( ) Substitute. = Simplify. The equation is