Pedro has a bag with 8 yellow marbles, 9 blue marbles, 12 green marbles, and 7 red marbles. What is the probability that Pedro will pull out a yellow or red marble?

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