document.write( "Question 958678: How do I solve this? \r
\n" ); document.write( "\n" ); document.write( "\"Philip drove 12 miles in town in the same time he drove 19 miles on the highway. His highway speed was 21 miles per hour faster than his speed in town. What was his average speed on the highway?\" \n" ); document.write( "

Algebra.Com's Answer #585895 by MathTherapy(10810) $\"\"$ $\"About$

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\n" ); document.write( "How do I solve this? \r
\n" ); document.write( "\n" ); document.write( "\"Philip drove 12 miles in town in the same time he drove 19 miles on the highway. His highway speed was 21 miles per hour faster than his speed in town. What was his average speed on the highway?\"
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Let speed on highway, be S
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document.write( "Then speed in town = S - 21
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document.write( "We then get: 
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document.write( "19(S - 21) = 12S -------- Cross-multiplying
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document.write( "19S - 399 = 12S
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document.write( "19S - 12S = 399
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document.write( "7S = 399
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document.write( "S, or speed on highway = , or  mph \n" );
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