document.write( "Question 176743: In a family there are two cars. The sum of the average miles per gallon obtained by the two cars in a particular week is 50 . The first car has consumed 30 gallons during that week, and the second has consumed 20 gallons, for a total of 1300 miles driven by the two cars combined. What was the average gas mileage obtained by each of the two cars in that week?
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Algebra.Com's Answer #131850 by Mathtut(3670) $\"\"$ $\"About$

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let x and y be the avg gas mileage of car 1 and car 2 respectively
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\n" ); document.write( "x+y=50...........eq 1
\n" ); document.write( "30x+20y=1300.....eq 2
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\n" ); document.write( "rewrite eq 1 to x=50-y and plug in the value to eq 2
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\n" ); document.write( "30(50-y)+20y=1300
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\n" ); document.write( "1500-30y+20y=1300
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\n" ); document.write( "-10y=-200
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\n" ); document.write( " $\"highlight%28y=20%29\"$ mpg car 2
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\n" ); document.write( "x=50-y $\"x=50-20=highlight%2830%29\"$ mpg car 1 \n" ); document.write( "

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