(x, y) is the ordered pair or the point of the line. The given problem is an example of a linear graph and its ordered pair represents (amount, number of gallons).
(3.75, 1) is one of the ordered pairs of the graph since $3.75 is the amount that you paid in 1 gallon of gas.
Moreover, $12 is the amount that Berto paid for the gas, we will divide it to $3.75 per gallon in order to get the number of gallon that is put in his car.
Solution: $12 / $ 3.75 per gallon= 3.2 gallons.
Therefore, another ordered pair on the graph of the line relating number of gallons of gas is (12, 3.2) since $12 is the amount that you paid for 3.2 gallons of gas.