A student draws two parabolas on graph paper. Both parabolas cross the x-axis at (-4.0) and (6, 0). The y-intercept of the first
parabola 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? Write your answer as a decimal rounded to the nearest tenth.