SOLUTION: Two cars leave the same point traveling in opposite directions. The second car travels 15 mph faster than the first. After 3 hours they are 465 miles apart. How fast is each car
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Question 550492: Two cars leave the same point traveling in opposite directions. The second car travels 15 mph faster than the first. After 3 hours they are 465 miles apart. How fast is each car traveling? Found 2 solutions by scott8148, asuar010:Answer by scott8148(6628) (Show Source):
You can put this solution on YOUR website! Since the cars have the initial starting point and they start at the same time... The total distance traveled is 465 miles... so d1 is the distance traveled by the first car and d2 is the dstance traveled by the second car... d1+d2=465 and time for both is 3... and since the second car is traveling 15 faster than the first one.. v2=v1+15
Then v1=d1/3 and v2=d2/3... by substituting v2 we get v1+15=d2/3 in the sencond formula...
Then v1=d2/3-15 as the second formula...
Then we make the first one equal to the second because both represent v1... so we obtain d1/3=d2/3-15... we multiply by 3 to get rid of the denominator and we get d1=d2-45 which is the same as d1-d2=-45; but we also have the expression that d1+d2=465... and by adding these two equations we obtain that 2d1=420 so
d1=210 so d2=255.. to get the velocities we divide both by 3 and we get v1=70 mph and v2=85 mph... PERCFECT!!! jajaja
