9.ella had softball and dance practice for 4 weeks. she practiced softball 2 hours a week and dance 1 hour a week. which operations can be used to find the total number of hours ella practiced softball and dance?

Astudent 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