Change 0.8-3 into a fraction

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 .

What are the domain and range of the function f(x)=2^x+1

Using the figure below, select the two pairs of alternate interior angles. a: point 1 and point 4 b : point 2 and point 3 c: point 6 and point 6d: point 5 and point 7