SOLUTION: A car at a certain speed travels 120 kilometers during the first part. On the second part, It reduces its speed by 10kph when it travels 100 kilometers. Find tge speed on each part

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A car at a certain speed travels 120 kilometers during the first part. On the second part, It reduces its speed by 10kph when it travels 100 kilometers. Find tge speed on each part      Log On


   



Question 1039970: A car at a certain speed travels 120 kilometers during the first part. On the second part, It reduces its speed by 10kph when it travels 100 kilometers. Find tge speed on each part of the part of the trip if the whole trip lasted 4 hours
Answer by jorel555(1290) About Me  (Show Source):
You can put this solution on YOUR website!
Let n be the slower speed. Then:
100/n+120/(n+10)=4
100n+1000+120n=4nē+40n
4nē-180n-1000=0
nē-45n-250=0
(n+5)(n-50)=0
n=50 kmh for the slower speed, 60 kmh for the faster speed!!!!!!!!!!!!