document.write( "Question 1031854: Andrea can ride her bike 2 mph faster than Ruby. It takes andrea 48 minutes less to travel 50 miles than it does Ruby. What is Andrea's rate in miles per hour? \n" ); document.write( "
Algebra.Com's Answer #646529 by mananth(16946)\"\" \"About 
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Andrea can ride her bike 2 mph faster than Ruby.\r
\n" ); document.write( "\n" ); document.write( "Let Ruby's rate be x
\n" ); document.write( "Andrea's rate = x+2\r
\n" ); document.write( "\n" ); document.write( "distance = 50 miles \r
\n" ); document.write( "\n" ); document.write( "Ruby's time - Andrea's time = 48 minutes => 4/5 hours\r
\n" ); document.write( "\n" ); document.write( "50/x - 50/(x+2) = 4/5\r
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\n" ); document.write( "\n" ); document.write( "50(x+2)-50x = x(x+2)*4/5\r
\n" ); document.write( "\n" ); document.write( "50x +100 -50x=(x^2+2x)4/5\r
\n" ); document.write( "\n" ); document.write( "100 = (4x^2 +8x)/5\r
\n" ); document.write( "\n" ); document.write( "500 = 4x^2 +8x\r
\n" ); document.write( "\n" ); document.write( "4x^2+8x-500=0\r
\n" ); document.write( "\n" ); document.write( "/4
\n" ); document.write( "x^2+2x-125 =0\r
\n" ); document.write( "\n" ); document.write( "x^2+2x+1 = 125+1\r
\n" ); document.write( "\n" ); document.write( "(x+1)^2 = 126\r
\n" ); document.write( "\n" ); document.write( "x+1 = +/- sqrt(126)\r
\n" ); document.write( "\n" ); document.write( "x= 10.22 mph\r
\n" ); document.write( "\n" ); document.write( "Andrea's speed = 12.22 mph\r
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