Divide thirty-one point five by ten

When y’all answer can y’all explain too !

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

Acircle has a radius of 17. approximately what is the area of the circle