Can someone explain/answer this? I think I know the answer but I want to be entirely sure

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 .

Steve wants to develop a way to find the total cost of any item including sales tax. the sales tax in his city is 6%. his friend jenna writes the expression x + 6x where x is the cost of the item. explain whether her expression is correct based on the situation.

The los angels ram scored 26, 30, 48, and 31 pts in their last four games. how many pts do they need to score in super bowl liii in order to have an exact mean average of 35 pts over five games. write and solve and equation. use x to represent the 5th game.