SOLUTION: Two boats leave the dock at the same time and travel in opposite directions. One travels 9 mph faster than the other. After 2 hours the boats are 170 miles apart. How fast is each

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Question 1124228: Two boats leave the dock at the same time and travel in opposite directions. One travels 9 mph faster than the other. After 2 hours the boats are 170 miles apart. How fast is each boat traveling?
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

Let x be the rate (the speed) of the slower motorboat, in miles-per-hour.
Then the rate of the faster motorboat is %28x%2B9%29mph.
the distance d=r%2At
after 2h:
d=2x->the slower motorboat
d=2%28x%2B9%29->the faster motorboat
since they travel in opposite directions, you need to add 2x%2B2%28x%2B9%29 to get how par the boats are apart
since given that the boats are 170 miles apart, your equation is
2x+%2B+2%28x%2B9%29+=+170

Simplify and solve the equation for x:
4x+%2B+18+=+170
4x+=+170+-+18
4x+=+152
x+=+152%2F4+=+38
The speed of the slower motorboat is 38mph.
The speed of the faster motorboat is 38%2B9+=+47mph.