F(x)=((1)/(3))^(x) Identify the key features of the exponential function

Click on the graphic until you find the right quotient. (36xa - 30xb) ÷ (-6x2)

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 .

In the rectangle below ac=30 units what is de