Aline intersects the point (13,-4) and (1,12).find the slope and simplify completely

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 .

If a baby uses 15 diapers in 2 days how many diapers will the baby use in a year

30 ! the graph shows the number of siblings different students have. select from the drop-down menus to correctly complete the statement.