Question

Jake and Seth put some money into their money boxes every week. The amount of money (y), in dollars, in their money boxes after a certain amount of time (x), in weeks, is shown by the equations below: Jake: y = 5x + 85 Seth: y = 20x + 40 After how many weeks will Jake and Seth have the same amount of money in their money boxes and what will that amount be?

Answer 1

5x + 85 = 20x + 40
15x = 45
    x = 3

5x + 85 = 5(3) + 85 = 15 + 85 = 100
20x + 40 = 20(3) + 40 = 60 + 400 = 100

answer

In 3 weeks  Jake and Seth will have the same amount of money in their money boxes. 
And it will that amount be $100