Evaluate: 4yº + xl if x = 8 and y = 7​

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 .

What is the solution to the equation? k/6.4=8.7 2.3 5.568 15.1 55.68

Valentina is subtracting from . she finds the lcd to be 15y2. what is valentina's next step?