document.write( "Question 1149181: Kristina went on a 220 mile trip to a soccer game. On the way back, due to road construction she had to drive 11 miles per hour slower. This made the trip take 1 hour longer. How fast did she drive to the soccer game? \n" ); document.write( "
Algebra.Com's Answer #770534 by VFBundy(438)\"\" \"About 
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To the game:
\n" ); document.write( "Distance = 220
\n" ); document.write( "Rate = r
\n" ); document.write( "Time = t = 220/r
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\n" ); document.write( "From the game:
\n" ); document.write( "Distance = 220
\n" ); document.write( "Rate = r - 11
\n" ); document.write( "Time = t + 1 = (220/r) + 1 = 220/(r - 11)
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\n" ); document.write( "(220/r) + 1 = 220/(r - 11)
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\n" ); document.write( "Cross-multiply:
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\n" ); document.write( "(r - 11)((220/r) + 1) = 220
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\n" ); document.write( "220 + r - 2420/r - 11 = 220
\n" ); document.write( "
\n" ); document.write( "209 + r - 2420/r = 220
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\n" ); document.write( "r - 2420/r = 11
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\n" ); document.write( "r²/r - 2420/r = 11
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\n" ); document.write( "(r² - 2420)/r = 11
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\n" ); document.write( "Cross-multiply:
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\n" ); document.write( "11r = r² - 2420
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\n" ); document.write( "r² - 11r - 2420 = 0
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\n" ); document.write( "(r - 55)(r + 44) = 0
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\n" ); document.write( "r = 55 and r = -44. Since the rate (r) cannot be a negative number, we are left with r = 55.
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\n" ); document.write( "To the game:
\n" ); document.write( "Rate = r = 55 mph \n" ); document.write( "
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