A phone plan charges $15.95 per month and $0.10 for every minute, m, that the phone is used. Mr. Kordemsky wants his phone bill for the month to be less than $40

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