Which expression is equivalent to (fg)(5)

What is the inverse of the function f(x)=4x+8

Need on this one asap im almost done with this subject

(10. in the figure, a aabc is drawn tocircumscribe a circle of radius 3 cm ,such thatthe segments bd and dc are respectively oflength 6 cm and 9 cm. find the length ofsides ab and ac.