Can someone me with this question

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 had 48 chocolates but he decided to give 8 chocolats to each of his f coworkers. how many chocolates does steve have left

Lana's family entered a 5-kilometer race lana's average step length is about 0.5 meter how many steps will she need to take the finish