The graphs of positive and negative x^2 parabolas will always have a domain of all real numbers. Even though you only have a portion of the graph and see a "restriction" on your domain values, it is incorrect to assume that the domain is limited to what you can see. As the branches of the parabola keep going up and up and up, the values of x keep getting bigger and bigger and bigger. Again, this is true for all + or - parabolas. ....... Can consider brainlist*:)
If there are 16 cups in one gallon, each gallon u add 16. If you have 3 gallons you add 16 3 times. So to get your answer you multiply 16 by three which is 48 cups.