Car A and Car B...Help?

Denna Prudente: x = gallons used by Car A, 75 - x = gallons used by Car BGallons used by Car A:35x + 20(75 - x) = 2,1007x + 4(75 - x) = 4207x + 300 - 4x = 4203x = 120x = 40Gallons used by Car B:= 75 - 40= 35Answer: Car A used 40 gallons; Car B used 35 gallons.Proof (total miles traveled by the cars, 2,100):= 35mpg(40g) + 20mpg(35g)= 1,400mi + 700mi= 2,100mi...Show more

Adrian Sherlin: 35i + 20j = 2100i + j = 75Solve the above system of equations to get i and j. i will be the gas used by the first car, and j will be the gas used by the second car.Car A used 40 gallons of gas and Car B used 35 gallons of gas....Show more

Sharie Sommerville: Let car A go 'A' miles in the week.Hence car B goes ( 2100 - A ) miles.Since car A goes 35 miles to a gallon , it uses A/35 gallons of gas.B uses ( 2100 - A ) / 20 gallons of gas.Since together they have used 75 gallons , you have :A/35 + (2100 - A)/20 = 7520A + 35(2100 - A) = 75 * 70020A + 73500 - 35A = 52500-15A = - 21000A ! = 1400 miles.Car B goes 700 miles.Hence car A uses 1400/35 gallons of gas = 40 gallons.Car B uses 35 gallons of gas....Show more

Simona Bulwinkle: Let car A go 'A' miles in the week.Hence car B goes ( 2100 - A ) miles.Since car A goes 35 miles to a gallon , it uses A/35 gallons of gas.B uses ( 2100 - A ) / 20 gallons of gas.Since together they have used 75 gallons , you have :A/35 + (2100 - A)/20 = 7520A + 35(2100 - A) = 75 * 70020A + 73500 - 35A = 52500-15A = - 21000A = 1400 miles.Car B goes 700 miles.Hence car A uses 1400/35 gallons of gas = 40 gallons.Car B uses 35 gallons of gas....Show more

Susan Rambo: x = the amount of gas car A used in one weeky = the amount of gas car B used in one weekgiven car A and car B travels 75 miles in one weekx + y = 7535x = number of miles car A traveled in that week20y = number of miles car B traveled in that weekgiven car A and car B traveled 2100 miles35x + 20y = 21so you have two equationsx + y = 7535x + 20y = 2100now just! solve for x and y...Show more