Amachine coats metal spheres with a plastic coating. the metal spheres have a radius of 9 mm the spheres formed by the metal and plastic coating have a radius of 12 mm.
how much plastic coating is on each sphere.
use 3.14 to approximate pi and express your answer in hundredths.

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