40xa^2 + 24 ax + 32 a =
all you have to do is factor out a 8a from each term
aka reverse distribution property
8a (5 a + 3x + 4)
The midpoint is (7,4.75) so the y-coordinate should be y=4.75. I hope that helps
A) the middle of the range is 39.5%
b) the difference between the middle and the ends of the range is ±1.5%
c) less than a majority favor change. Change seems unlikely.