Unlike the others, the 'a' values aren't all correctly placed.
The a = -4 in the middle is correctly placed, since it's the only parabola that opens downward. This applies whenever a < 0.
The left and right items are incorrectly placed. The more narrow graph needs to have a = 1. The further 'a' is from zero, the more narrow the parabola.
<h3>In short, you need to swap the a = 1 and a = 0.25</h3>
Bill's statement is only true if 1 or both of the variables are positive but if both r and s are negative then it will be located on the left of r. Ex. r=-1 s=-2 (-1)+(-2)=-3