SOLUTION: On a 570-mile trip, Andy averaged 5 miles per hour faster for the last 240 miles than he did for the first 330 miles. The entire trip took 10 hours. How fast did he travel for the
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Question 366971: On a 570-mile trip, Andy averaged 5 miles per hour faster for the last 240 miles than he did for the first 330 miles. The entire trip took 10 hours. How fast did he travel for the first 330 miles? Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! first 330 miles speed be x mph
time taken = 330/x
...
240 miles speed = x+5 mph
distance = 240
time = 240/(x+5)
..
330/x + 240/(x+5)=10
330x+1650+240x / x(x+5)=10
570x+1650 = 10x^2+50x
10x^2-520x-1650=0
/10
x^2-52x-165=0
x^2-55x+3x-165=0
x(x-55)+3(x-55)=0
(x-55)(x+3)=0
So x = 55 mph first 330 miles
