Simplify: -12x + 4y- 6y + 10x - 25 5x - 2(x - 12)​

What aspects of lines have to be diffrent

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 .

Write an equation in point-slope form for the line through the given point that has the given slope (-2,-7); m=-3/2