Alocal hamburger shop sold a combined total of 639 hamburgers and cheeseburgers on monday. there were 61 fewer cheeseburgers sold than hamburgers. how many hamburgers were sold on monday?

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