document.write( "Question 105531: In a family there are two cars. In a given week, the first car gets an average of 15 miles per gallon, and the second car gets 40 miles per gallon. The two cars combined drive a total of 65 miles in that week, for a total gas consumption of 1600 gallons. How many gallons were consumed by each of the two cars that week?
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Algebra.Com's Answer #76865 by ptaylor(2198)\"\" \"About 
You can put this solution on YOUR website!
Let x=miles driven by the 15 mpg car
\n" ); document.write( "Then 15x=amount of gas used by the 15 mpg car\r
\n" ); document.write( "\n" ); document.write( "And 65-x=miles driven by the 40 mpg car
\n" ); document.write( "Then 40(65-x)=amount of gas used by the 40 mpg car\r
\n" ); document.write( "\n" ); document.write( "Now we are told that together the two cars use 1600 gallons. So our equation to solve is:\r
\n" ); document.write( "\n" ); document.write( "15x+40(65-x)=1600 get rid of parens\r
\n" ); document.write( "\n" ); document.write( "15x+2600-40x=1600 subtract 2600 from both sides\r
\n" ); document.write( "\n" ); document.write( "15x+2600-2600-40x=1600-2600 collect like terms\r
\n" ); document.write( "\n" ); document.write( "-25x=-1000 divide both sides by -25
\n" ); document.write( "x=40 miles--------------------miles driven by the 15 mpg car\r
\n" ); document.write( "\n" ); document.write( "65-x=65-40=25 miles -----------miles driven by the 40 mpg car\r
\n" ); document.write( "\n" ); document.write( "CK\r
\n" ); document.write( "\n" ); document.write( "40*15+25*40=1600\r
\n" ); document.write( "\n" ); document.write( "600+1000=1600
\n" ); document.write( "1600=1600\r
\n" ); document.write( "\n" ); document.write( "Hope this helps----ptaylor
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