Idon't know what to do on this question and it's due tomorrow

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 .

Kathleen's gross annual salary is $56,820. what is the maximum amount of rent she can afford to pay? round your answer to the nearest dollar. question 1 options: $1146 $1326 $1656 $2368

For what values of x is x2 + 2x = 24 true?