Jenna uses 1/2 yard of ribbon for each box she wraps. How many inches of the ribbon des she need to wrap 4 boxes? Use the linear model to help solve.

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 .

Which expression is equivalent to sq-80

Factor and solve to find roots x squared -x - 90 =0