A car has 10 gallons of gas. Sandy adds 0.25 gallons per second. Which shows how much gas (y) is in the car after (x) seconds?

I don't see anything, but here's the equation...

y = 10 + .25x   where x is the number of seconds and "y' is the number of gallons after "x"  seconds....

.25 is a quarter of one, so if x=4 then y=1