SOLUTION: I need help. I know that this has to do with time, Distance and rate, but I am having a problem setting up this problem and where do I put the X. Shannon drove 45MPH to her siste

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Question 787298: I need help. I know that this has to do with time, Distance and rate, but I am having a problem setting up this problem and where do I put the X. Shannon drove 45MPH to her sister vanessas house, she stayed for lunch which was 1 1/2 hours, then shannon drove home at 55MPH. The whole trip including lunch was 4 hours. How far does shannon live from vanessa?
Answer by josgarithmetic(39838) About Me  (Show Source):
You can put this solution on YOUR website!
You just account for time and rely on movement using rate*time=distance.
r%2Ah=d for rate, time in hours, distance in miles.
divide both sides by r and have: h=d%2Fr

The time traveling was 4-1%261%2F2 hours.
Times for going and returning are unknowns, x and y.
45*x+55*y= distance that you do not know, say d.
45x%2B55y=d
and x%2By=2%261%2F2

So far, your problem is incomplete. You have THREE variables but only TWO equations.