Question

Problem page a family has two cars. the first car has a fuel efficiency of 30 miles per gallon of gas and the second has a fuel efficiency of 20 miles per gallon of gas. during one particular week, the two cars went a combined total of 1100 miles, for a total gas consumption of 45 gallons. how many gallons were consumed by each of the two cars that week?

Answer 1

You will have 2 equations.
30x+20y=1100
and 
x+y=45
by putting it into standard form
-(30/20)x+55=y 
you can now solve finding the answer to be 20 for x and 25 for y.
Plug it into the original equation to find it correct and then plug it into x+y
20+25=45
30*20+25*20=1100