A company charters a party boat that normally costs $56 per person. A group discount reduces the fare by $0.70 for each ticket sold. The more tickets sold, the lower is the per-person fare. The maximum capacity of the boat is 80 people, including the crew of 10 people. What size of group would maximize the boat company's revenue? SOMEONE PLEASE HELP

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