For a regular tessellation, the shapes can be duplicated infinitely to fill a plane such that there is no gap. The only shapes that can form regular tessellations are equilateral traingle(all sides are equal. This means that it can be turned to any side and it would remain the same), square and regular hexagon. Looking at the given options, we have
Shape Tessellate?
Octagon No
Hexagon Yes
Pentagon No
Square Yes
Triangle No(unless it is specified that it is an equilateral triangle)
So since the vertex falls onto the axis of symmetry, we can just solve for that to get the x-coordinate of both equations. The equation for the axis of symmetry is
, with b = x coefficient and a = x^2 coefficient. Our equations can be solved as such:
y = 2x^2 − 4x + 12: 
y = 4x^2 + 8x + 3: 
In short, the vertex x-coordinate's of y = 2x^2 − 4x + 12 is 1 while the vertex's x-coordinate of y = 4x^2 + 8x + 3 is -1.
Let the attendees in opposition be x. This means that the attendees in favour are x+6.
That means x+x+6=42, which is 2x+6=42, so 2x=36 and x=18. Therefore, there are 18 attendees who opposed it.
The x=7y-4 one and put it to where the x in the other equation is.
When forming a perfect square trinomial you need to "complete the square".
All of the steps to completing the square when solving an equation:
1. The leading coefficient must be 1.
2. Divide b by 2.
3. Square (b/2)
4. Add (b/2)^2 to both sides to keep the polynomial balanced.
5. You can now write the perfect square trinomial and solve.
x^2 - 3x
-3/2
(-3/2)^2 = 9/4 = 2 1/4
LETTER B