<PRE><B>Question 831866</B>
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s = d/t
d = s*t
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outbound:
4800 = st
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return:
4800 = (s - 200)(t + 2)
4800 = st + 2s - 200t - 400
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st = st + 2s - 200t - 400
2s - 200t = 400
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s = 4800/t
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2s - 200t = 400
2(4800/t) - 200t = 400
9600/t - 200t = 400
9600 - 200tt = 400t
-200tt - 400t + 9600 = 0
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the above quadratic equation is in standard form, with a=-200, b=-400, and c=9600
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to solve the quadratic equation, by using the quadratic formula, copy and paste this:
-200 -400 9600
into this solver: https://sooeet.com/math/quadratic-equation-solver.php
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the quadratic has two real roots at:
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x = -8
x = 6
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the negative root doesn&#39;t fit the problem statement, so use the positive root
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x = 6 hours
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answer:
speed outbound:
s = 4800/6
s = 800 kph
speed on return:
s = 4800/8
s = 600 kph
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Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
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Solve quadratic equations, quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
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Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php</PRE>