can anyone answer this question?

Question

anonymous · Answer

A family has two cars. The first car has a fuel efficiency of  15 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 1275miles, for a total gas consumption of 50 gallons. How many gallons were consumed by each of the two cars that week?

anonymous · Answer

I couldn't get an answer, but I tried these equations: $$15x+30y=50gal$$ (where x=number of miles driven by car 1 and y=number of miles driven by car 2) $$x+y=1275mi$$
Then I moved x over on the second equation, plugged that new equation into the first equation, and solved for x. I got a huge number.

I then plugged that number back into the first equation and got a negative number for y (which probably shouldn't have happened).

I don't know, but you can start out with this idea.

mertsj · Answer

x+y=50
15x+30y=1275

mertsj · Answer

15(50-y)+30y=1275
750-15y+30y=1275
15y=525
y=35 gallons consumed by the 30 mile per gallon car
x=15 gallons consumed by the 15 miles per gallon car

anonymous · Answer

Yay for teamwork! :)

mertsj · Answer

yep