What is the value of ?

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 .

Consider the polynomials given below. p(x) = x4 + 3x3 + 2x2 – x + 2 q(x) = (x3 + 2x2 + 3)(x2 – 2) determine the operation that results in the simplified expression below. 35 + x4 – 573 - 3x2 + x - 8 a. p+q b. pq c.q-p d. p-q

The graph below shows the line of best fit for data collected on the number of cell phones in cell phone cases sold at the local electronic store on four different days