SOLUTION: A train from London to Birmingham takes 2 hours for the journey. If the average speed of the train were decreased by 5 miles per hour, the train would take 12 minutes longer. Find

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Question 935602: A train from London to Birmingham takes 2 hours for the journey. If the average speed of the train were decreased by 5 miles per hour, the train would take 12 minutes longer.
Find the distance from London to Birmingham and the average speed of the train, using simultaneous equations
Found 2 solutions by TimothyLamb, josmiceli:
Answer by TimothyLamb(4379) (Show Source):
You can put this solution on YOUR website!
x = distance between the cities (miles)
y = speed of the train (mph)
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s = d/t
t = d/s
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at normal speed:
y = x/2
2y = x
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at reduced speed:
y - 5 = x/(2 + 12/60)
y - 5 = x/2.2
2.2y - 2.2*5 = x
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put the system of linear equations into standard form
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x - 2y = 0
x - 2.2y = -11
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copy and paste the above standard form linear equations in to this solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
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solution:
x = distance between the cities (miles) = 110
y = speed of the train (mph) = 55
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Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website!

is in miles
is in mi/hr
is in hours
(1)
(2)
(2)
------------------------------
Substitute (1) into (2)
(2)
(2)
(2)
(2)
and
(1)
(1)
(1)
It is 110 mi from London to Birmingham
The train's average speed is 55 mi/hr