Two trains leave the station at the same time one heading east one heading west. the eastbound train travels at 85 miles per hour. the westbound train travels at 105 miles per hour. how long will it take for the two trains to be 456 miles apart

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 .

If x = -2, then x 2-7x+10 equals a. 0 b.20 c.28

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15