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

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: A car at a certain speed travels 120 kilometers during the first part. On the second part, it reduces its speed by 10 kph when it travels 100 kilometers. Find the speed on each par      Log On


   

Question 1095688: A car at a certain speed travels 120 kilometers during the first part. On the second part, it reduces its speed by 10 kph when it travels 100 kilometers. Find the speed on each part of the trip if the whole trip lasted for 4 hours.
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
               SPEED         TIME           DISTANCE

firstpart      r+10         120%2F%28r%2B10%29     120

secondpart     r            100%2Fr       100

Total                        4

Solve the equation 120%2F%28r%2B10%29%2B100%2Fr=4.

-
30%2F%28r%2B10%29%2B25%2Fr=4
.
.