SOLUTION: You are biking at a speed of 18 miles per hour. You are 3 miles behind your friend who is biking at a speed of 12 miles per hour. Write and solve an equation to find the amount of

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: You are biking at a speed of 18 miles per hour. You are 3 miles behind your friend who is biking at a speed of 12 miles per hour. Write and solve an equation to find the amount of       Log On

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Question 788093: You are biking at a speed of 18 miles per hour. You are 3 miles behind your friend who is biking at a speed of 12 miles per hour. Write and solve an equation to find the amount of time it takes for you to catch up with your friend
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +d+ = your friends distance in miles when
you catch up
Let +t+ = time in hrs when you catch up
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Your equation:
(1) +d+%2B+3+=+18t+
Friend's equation:
(2) +d+=+12t+
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Substitute (2) into (1)
(1) +12t+%2B+3+=+18t+
(1) +6t+=+3+
(1) +t+=+1%2F2+
You catch up in 1/2 hour
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check:
(1) +d+%2B+3+=+18%2A%281%2F2%29+
(1) +d+=+9+-+3+
(1) +d+=+6+
and
(2) +d+=+12%2A%281%2F2%29+
(2) +d+=+6+
OK