SOLUTION: A jet plane, flying 80 mph faster than a propeller plane, travels 3960 miles in 2 hours less time than the propeller plane takes to fly the same distance. How fast does each plane
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Question 831317: A jet plane, flying 80 mph faster than a propeller plane, travels 3960 miles in 2 hours less time than the propeller plane takes to fly the same distance. How fast does each plane fly? Answer by josgarithmetic(39618) (Show Source):
http://www.algebra.com/algebra/homework/Average/Average.faq.question.831176.html
and
Same general problem but just different example: Look-up problem number 830872
http://www.algebra.com/algebra/homework/word/travel/Travel_Word_Problems.faq.question.830872.html
--------------------REQUEST FOR SOLUTION WAS STRONGLY DESIRED----------HERE!-----
The data table went like this:
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_____________speed____________time____________distance
Jet__________r+80_____________h-2_______________3960
Propeller____r_________________h________________3960
R*t=d the uniform rates equation for travel, R meaning rate, t for time, d for distance.
JET: (r+80)(h-2)=3960;
PROP: rh=3960.
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Use the simpler equation in two ways. For substitution directly for and in the form of
.
Using , the jet equation is
Substituting for , obtain
Substitute for h FROM the simpler equation
Using the general solution for a quadratic equation but omitting the expression and steps:
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Propeller Plane
r=360 mph
h=11 hours
Jet Plane
r+80=440 mph
h-2=9 hours
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