Find the value of √14/6

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 i have a 24 in loaf of bread and i cut it into two pieces one 9 in how long was the other

The quadratic function h(t)=-16.1t^2+150 choose the graph representation