SOLUTION: Lerry drove 329 miles in 2 hours more then it took Terrell to drive 260 miles. Terrell drove at and average reate of 5 miles per hour faster then Larry. How fast did Larry travel?
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-> SOLUTION: Lerry drove 329 miles in 2 hours more then it took Terrell to drive 260 miles. Terrell drove at and average reate of 5 miles per hour faster then Larry. How fast did Larry travel?
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Question 166236: Lerry drove 329 miles in 2 hours more then it took Terrell to drive 260 miles. Terrell drove at and average reate of 5 miles per hour faster then Larry. How fast did Larry travel? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Lerry drove 329 miles in 2 hours more then it took Terrell to drive 260 miles.
Terrell drove at an average rate of 5 miles per hour faster then Larry.
How fast did Larry travel?
:
Let s = Larry's speed
then
(s+5) = Terry's speed
:
Write a time equation: Time = dist/speed
:
L's time - 2 hr = T's time - 2 =
:
Multiply equation by s(s+5)
s(s+5)* - 2s(s+5) = s(s+5)*
:
This eliminates the denominators and you have:
329(s+5) -2s^2 - 10s = 260s
:
329s + 1645 - 2s^2 - 10s - 260s = 0; arrange as a quadratic on the left
:
-2s^2 + 329s - 260s - 10s + 1645 = 0
:
-2s^2 + 59s + 1645 = 0
:
Easier to factor if change the signs, mult by -1
2s^2 - 59s - 1654
Factors to:
(2s + 35)(s - 47) = 0; use the quadratic formula if you need to:
Positive solution
s = 47 mph is L's speed
then
47 + 5 = 52 mph is T's speed
:
:
Check solution by finding the travel time of each
329/47 = 7 hr
260/52 = 5 hr
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differ = 2 hrs as given
