Which of the following equations demonstrates the associative property? A: -5(4+3i)=-20-15i
B: 4+6i=6i+4
C: 7i+0=7i
D: (2+3i)+5=2+(3i+5)

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