How do I complete the square of $y= -4x^2-2x-4$? $y = -4x^2 - 2x - 4$ 
I just can't figure this out, do I divide the second number and the third number by $4$ then by $2$ and then add the product to the second one and subtract it from the third one?

In general, if you want to complete the square on $ax^2+bx+c$, here's the formula and derivation
Suppose that
$$ax^2+bx+c=A(x+B)^2+C$$
Then:
$$ax^2+bx+c=Ax^2+2ABx+AB^2+C$$
Therefore:
$$A=a$$
$$b=2aB$$
$$c=aB^2+C$$
Therefore:
$$B=\frac{b}{2a}$$
$$C=-a(\frac{b}{2a})^2+c=-\frac{b^2}{4a}+c$$
Plug it all in:
$$ax^2+bx+c=a(x+\frac{b}{2a})^2+c-\frac{b^2}{4a}$$
Which is the complete square.
