Solve for x LOOK AT PIC!! Thanks

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 inequality? 6x−5> −29, a x> −4 bx> 4 cx< 4 dx< −4

45 was divided by a power of ten to get 4.5. what power of ten was it divided by? people 4.5