Question 266105
Two cars start at the same point and travel in opposite directions. One car travels 5 mph faster than the other car. After 4 hrs, the two cars are 420 miles apart. Find the speed of each car. 
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Their combined speed is 420/4 = 105 mph
x + y = 105 (combined)
x - y = 5  (difference)
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2x = 110
x = 55
Speeds = 55 and 50