SOLUTION: A train leaves a station and travels north at a speed of 50 mph. Five hours​ later, a second train leaves on a parallel track and travels north at 175 mph. How far from the s

Algebra ->  Equations -> SOLUTION: A train leaves a station and travels north at a speed of 50 mph. Five hours​ later, a second train leaves on a parallel track and travels north at 175 mph. How far from the s      Log On


   



Question 1076973: A train leaves a station and travels north at a speed of 50 mph. Five hours​ later, a second train leaves on a parallel track and travels north at 175 mph. How far from the station will they​ meet?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Find the head start in miles for the 1st train
+d%5B1%5D+=+50%2A5+
+d%5B1%5D+=+250+ mi
------------------------
Let +d+ = distance in miles the 2nd train
travels until they meet
Let +t+ = time in hrs after 2nd train leaves
until they meet
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Equation for 1st train:
(1) +d+-+250+=+50t+
Equation for 2nd train:
(2) +d+=+175t+
-----------------------
Plug (2) into (1)
(1) +175t+-+250+=+50t+
(1) +125t+=+250+
(1) +t+=+2+
and
(2) +d+=+175t+
(2) +d+=+175%2A2+
(2) +d+=+350+
They will meet 350 mi from the station
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check:
(1) +d+-+250+=+50t+
(1) +d+-+250+=+50%2A2+
(1) +d+=+250+%2B+100+
(1) +d+=+350+
OK