HELP ME PLZ BRAINIEST TO WHOEVER RIGT

Iam trying to solve a linear equation for the shoe size of someone 84" tall taking into consideration example 1 is 69" tall with a shoe size of 9 and example 2 is 72 inches tall with a shoe size of 11. i understand that the equation should be y=mx+b and that on the graph the answer is (3,2) but i just don't understand how to create the equation to solve for 84-inches and 60-inches tall questions. after two days, i need .

F(x)= 4x g(x) =x-1 what is f(x) divided by g(x)

Vinay constructed this spinner based on the population of teachers at his school according to vinays model what is the probability that he will have a male history teacher two years in a row