Maurice drove 400 km from Edmonton to Battleford in 1 hour less time than it took Martin to drive the same route from Battleford to Edmonton. If Maurice drove 20 km/h faster than Martin, at what speed did each of them drive?
Show a complete algebraic solution.
Let Maurice's speed be V1
Let Martin's speed be V2
V1 = V2 + 20
elapsed times:
Morris' time = Martin's time + 1
400/V2 = 400/V1 + 1
Susbtitute for V1:
400/V2 = 400/(V2 + 20) + 1
Solve for V2; then V1
so now where do I go???
sorry my computer shut down. hold up real quick and let me re type my answer.
okay you're gonna solve for V2. you've got your problem which is
400/V2 = 400/(V2 + 20) + 1
now you isolate V2. do youknow how to do that?
well not exactly. It has me boggled this one.
could you show me?
lol. okay well first lets look at your equation.
400/v2 = 400/(v2+20) + 1
first thing is you always get rid of the denominator. remember, what u do to one side of the equal sign you do to the other side. so we are going to multiply both sides by v2. this will cancel out one of the denominators.
v2(400/v2)= v2(400/(v2+20) + 1)
it will cancel out the denominator of the fraction on the left side of the equal sign and all we have left is 400. if you don't understand why then just tell me and i'll explain.
next we distribute the v2 on the right side of the equal sign.
400= 400v2/(v2+20) + 1v2
now we get rid of the denominator by doing the same thing we did earlier. mulitply it, which cancels it out on the fraction. so now you have
400v2= 400v2 + 1v2
now solve for v2 by adding the 400v2 and the 1v2. then solve. if you need further help than just say the word.
so does the answer come out to:
v2 = 1.0025
oops, i forgot to type the 4000. sorry. okay i'm going back a little and i'll explain all the way:
400= 400v2/(v2+20) + 1v2
now we get rid of the denominator by doing the same thing we did earlier. mulitply it, which cancels it out on the fraction. so now you have
400v2 + 8000= 400v2 + 1v2
now solve for v2 by adding 400v2 and 1v2 together, which is 401v2. so you have:
400v2 + 8000= 401v2
now get the all the v2's on one side, by moving the 400v2 over to the right side of the equal sign. subtract to move it. remember, what ever we do to one side of the equal side do to the other side:
400v2 + 8000= 401v2
-400v2 -400v2
so now it looks like this:
8000= 401v2 - 400v2
subtract the 401v2 and the 400v2 and you get:
8000= 1v2
and 1v2 is the same thing as v2, so:
8000= v2
thanks, that makes a whole lot more sense!!!
i'm glad it does! sorry about the mess up. :)