SOLUTION: Christine drives her car 495 miles and has an average of a certain speed. If the average speed had been 2mph more, she could have traveled 517 miles in the same length of time. Wha

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Question 1157861: Christine drives her car 495 miles and has an average of a certain speed. If the average speed had been 2mph more, she could have traveled 517 miles in the same length of time. What was her average speed?

Found 2 solutions by josmiceli, MathTherapy:
Answer by josmiceli(19441)   (Show Source): You can put this solution on YOUR website!
Let = her actual speed in mi/hr
Let = her actual time
-----------------------------------
(1)
(2)
---------------------------------
(1)
Plug this into (2)
(2)
(2)
(2)
(2)
Here average speed was 45 mi/hr
Answer by MathTherapy(10555)   (Show Source): You can put this solution on YOUR website!

Christine drives her car 495 miles and has an average of a certain speed. If the average speed had been 2mph more, she could have traveled 517 miles in the same length of time. What was her average speed?
Doesn't have to be as complex, and with large numbers as the other person would have you believe.



Let the speed be S

Then we get the following TIME equation: 

  ------ Reducing the fractions by factoring out the numerator-GCF, 11

47S = 45(S + 2) ------- Cross-multiplying

47S = 45S + 90

47S - 45S = 90

2S = 90

Average speed or  

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