SIMPLE GEOMETRY PROBLEM PLEASE HELP, 20 POINT QUESTION!!! WILL MARK BRAINLIEST.

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 .

Solve with work adding cheese to a mcdonalds quarter pounder increases the fat content from 21g to 30g. what is the percent of change ?

What is the expression in factored form? 3x^2 + 18x + 24 a. 3(x+2)(x+4) b. 3(x-2)(x+4) c. 3(x-2)(x-4) d. 3(x+2)(x-4)