document.write( "Question 375952: A family has two cars. The first car has a fuel efficiency of 40 miles per gallon of gas and the second has a fuel efficiency of 30 miles per gallon of gas. During one particular week, the two cars went a combined total of 1650 miles, for a total gas consumption of 45 gallons. How many gallons were consumed by each of the two cars that week? \n" ); document.write( "
Algebra.Com's Answer #267379 by mananth(16946)![]() ![]() You can put this solution on YOUR website! A family has two cars. The first car has a fuel efficiency of 40 miles per gallon of gas and the second has a fuel efficiency of 30 miles per gallon of gas. During one particular week, the two cars went a combined total of 1650 miles, for a total gas consumption of 45 gallons. How many gallons were consumed by each of the two cars that week? \n" ); document.write( ".. \n" ); document.write( "one car 40 miles /gallon \n" ); document.write( "other car 30 miles/gallon \n" ); document.write( ".. \n" ); document.write( "Total miles = 165 \n" ); document.write( "gas used = 45 gallons \n" ); document.write( "... \n" ); document.write( "let first car drive x miles \n" ); document.write( "second car drive y miles \n" ); document.write( ".. \n" ); document.write( "x/40 + y/30 = 45 \n" ); document.write( "(30x+40y)/30*40 = 45 \n" ); document.write( "30x+40y = 45*40*30 \n" ); document.write( "30x+40y=54,000............................1 \n" ); document.write( "x+y = 1650...............................2 \n" ); document.write( "multiply (2) by -30 \n" ); document.write( "-30x-30y= 1650*-30 \n" ); document.write( "-30x-30y=-49,500\r \n" ); document.write( "\n" ); document.write( "add to (1) \n" ); document.write( "10y=4500 \n" ); document.write( "/10 \n" ); document.write( "y=450 miles \n" ); document.write( "average = 30 \n" ); document.write( "consumption = 450/30 \n" ); document.write( "= 15 gallons \n" ); document.write( "x= 1650-450=1200 miles \n" ); document.write( "first car 1200/40 = 30 gallons\r \n" ); document.write( "\n" ); document.write( "... \n" ); document.write( "m.ananth@hotmail.ca \n" ); document.write( " \n" ); document.write( " |