You buy a bag of dog food for $12.59 and a bottle of dog shampoo for $4.75 how much more did the dog food coast than the shampoo

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