I need help with these four quetions

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?

Aplane is taking off from bangladesh headed to new york city. at the same time, a plane from new york city is headed to bangladesh is also taking off. the plane bound to new york city is traveling at 600 mph, while the plane traveling to bangladesh is traveling at 400 mph. how far from new york city will the two planes meet if the distance between new york city and bangladesh is 8,000 miles?

Need on this geometry question. explain how you did it.