27 X 9^3x can be written in the form 3k where k is an expression in terms of x. What is k

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 .

Find the derivative of the function

Write the ratio as a fraction in lowest terms 1 1/2 to 3 1/3