Ahumidifier uses 30 gallons of water in 8 hours. if the total amount of water available is 45 gallons, how many gallons of water would be left after 7 hours?

Astudent draws two parabolas both parabolas cross the x axis at (-4,0) and (6,0) the y intercept of the first parabolas is (0,-12). the y intercept of the second parabola is (0,-24) what is the positive difference between the a values for the two functions that describe the parabolas