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?

3 weeks, $100
3 weeks, $285
6 weeks, $150
100 weeks, $3

Answer 1

1)  How many weeks will Jake and Seth be equal? set the equations equal to each other and solve for x:

5x + 85 = 20x + 40

45 = 15x

x = 3 weeks

2)  How much money will that be? plug x = 3 back into the equation to solve for y:

Jake:  5(3) + 85 = $100
Seth:  20(3) + 40 = $100

answer is $100

Answer 2

After how many weeks will jake and seth have the same amount of money
jake=y=5x+85
seth=y=20x+40
so when seth=jake or y=y or 5x+85=20x+40 then they have same ammount of money so solve for when they are equal
5x+85=20x+40
subtract 40 from both sides
5x+45=20x
subtract 5x from both sides
45=15x
divide boht isdes yb 15
3=x

after 3 weeks

then subsitute 3 into the equation
20x+40=y
20(3)+40=y
60+40=y
100=y

the answer is
3 weeks, $100