SOLUTION: Carlos can walk 8 miles in the same time it takes him to jog 12 miles. His jogging rate is 5 miles per hour faster than his walking rate. At what rate does he walk? How long does i

Algebra ->  Equations -> SOLUTION: Carlos can walk 8 miles in the same time it takes him to jog 12 miles. His jogging rate is 5 miles per hour faster than his walking rate. At what rate does he walk? How long does i      Log On


   

Question 178777: Carlos can walk 8 miles in the same time it takes him to jog 12 miles. His jogging rate is 5 miles per hour faster than his walking rate. At what rate does he walk? How long does it take him to walk 8 miles?
Answer by HyperBrain(694) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=time it takes to walk 8 mi or jog 12 mi
distance=rate*time
rate=distance/time
Therefore,
8%2Fx=his walking speed
12%2Fx=jogging speed
His jogging rate is 5 miles per hour faster than his walking rate.
So,
12%2Fx=8%2Fx%2B5
12%2Fx=8%2Fx+%2B5x%2Fx
12%2Fx=%285x%2B8%29%2Fx
x(5x+8)=12x
5x^2+8x=12x
5x^2-4x=0
5x-4=0
x=4/5
walking rate=8%2Fx=8%2F%284%2F5%29=8%285%2F4%29=2%2A5=10mi per hr
x=4/5=time it takes to walk 8 miles.
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