I was originally going to graph the two equations, but I don't have graph paper so I set the equations equal to each other.
so Mr.Reeds equation is: y=70x+4.5 and Mrs.Reeds equation is: y=85x
so if I set these equal to each other I would minus the 70x from both sides leaving me with 15x = 4.5. Now since that's done I would divide everything by 15 which will cause me to get a fraction. So once that's done I would be left with x=3/10. I hope this helped!