document.write( "Question 195292: In a family there are two cars. In a given week, the first car gets an average of 30 miles per gallon, and the second car gets 40 miles per gallon. The two cars combined drive a total of 2500 miles in that week, for a total gas consumption of 70 gallons. How many gallons were consumed by each of the two cars that week? \n" ); document.write( "
Algebra.Com's Answer #146494 by checkley77(12844)\"\" \"About 
You can put this solution on YOUR website!
x/30+(2,500-x)/40=70
\n" ); document.write( "(40x+30(2,500-x))/(30*40)=70
\n" ); document.write( "(40x+75,000-30x)/1,200=70
\n" ); document.write( "10x+75,000=70*1,200
\n" ); document.write( "10x+75,000=84,000
\n" ); document.write( "10x=84,000-75,000
\n" ); document.write( "10x=9,000
\n" ); document.write( "x=9,000/10
\n" ); document.write( "x=900 miles for the 30 mpg car.
\n" ); document.write( "2500-900=1,600 for the 40 mpg car.
\n" ); document.write( "Proof:
\n" ); document.write( "900/30+1,600/40=70
\n" ); document.write( "30+40=70
\n" ); document.write( "70=70
\n" ); document.write( "
\n" );