Confused at "Evaluate the algebraic expression 6g - 11 for g = – 5". How am I supposed to evaluate?

Afunction is given: f(x)=3x+12 a. determine the inverse of this function and name it g(x) b. use composite functions to show that these functions are inverses. c. f(g(– explain: what is the domain?

Having a hard time understanding this question (see attachment).

Will mark name all segments skew to bc