document.write( "Question 241510: You drove 56 miles on a service call for your company and it took 10 minutes longer than the return trip when you drove an average of 8 miles per hour faster. What was your average speed on the return trip? \n" ); document.write( "
Algebra.Com's Answer #176884 by stanbon(75887)\"\" \"About 
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You drove 56 miles on a service call for your company and it took 10 minutes longer than the return trip when you drove an average of 8 miles per hour faster. What was your average speed on the return trip?
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\n" ); document.write( "Service Call DATA:
\n" ); document.write( "distance = 56 miles ; rate = x mph ; time = d/r = 56/x hrs
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\n" ); document.write( "Return trip DATA:
\n" ); document.write( "distance = 56 miles ; rate = (x+8) mph ; time = 56/(x+8) hrs
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\n" ); document.write( "Equation:
\n" ); document.write( "go time - return time = 1/6 hr
\n" ); document.write( "56/x - 56/(x+8) = 1/6
\n" ); document.write( "1/x - 1/(x+8) = 1/336
\n" ); document.write( "Multiply thru by 336x(x+8) to get:
\n" ); document.write( "336(x+8) - 336x = x(x+8)
\n" ); document.write( "336*8 = x^2+8x
\n" ); document.write( "x^2 + 8x - 2688 = 0
\n" ); document.write( "(x-48)(x+56) = 0
\n" ); document.write( "Positive solution:
\n" ); document.write( "x = 48 mph (rate on the service call)
\n" ); document.write( "x+8 = 56 mph (rate on the return)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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