SOLUTION: My problem is a bus from London to Penzance leaves London at 13.00 hours and travels at 60km/h. A car averaging 80km/h leaves London by the same route an hour later. Find graphic

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: My problem is a bus from London to Penzance leaves London at 13.00 hours and travels at 60km/h. A car averaging 80km/h leaves London by the same route an hour later. Find graphic      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 858632: My problem is a bus from London to Penzance leaves London at 13.00 hours and travels at 60km/h.
A car averaging 80km/h leaves London by the same route an hour later.
Find graphically when the car overtakes the bus

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
let x = number of hours
let y = number of kilometers
for the bus, y = 60x
for the car, y = 80(x-1)
what happens is:
when x = 0, the bus is at 0 miles traveled.
when x = 1, the car is at 0 miles traveled.
disregard any negative values below x-axis or to the left of the y-axis as those are invalid values because the number of hours can't be less than 0 and the number of miles can't be less than 0.
the only reason they are shown is to show the x-axis values and the y-axis values.
if the graph is shown starting at 0, you wont' be able to see them.
the graph below the first graph shows you what i mean.
it's the same graph but the x-axis starts at 0 and the y-axis starts at 0.
you can see that, while the second graph is technically more correct since negative values are not allowed, the values on the y-axis and the x-axis don't show up which is why the first graph shows some negative values as well even though they are not valid.
first graph is shown below:
graph%28600%2C600%2C-1%2C5%2C-100%2C400%2C60x%2C80%28x-1%29%29
second graph is shown below:
graph%28600%2C600%2C0%2C5%2C0%2C400%2C60x%2C80%28x-1%29%29