Problem:$\displaystyle 4x^2 + 4x +y^2 = 0$

I graph it and I get an elipse, but I cant figure out how to get it into the form:

$\displaystyle \frac{x^2}{a^2} + \frac{y^2}{b^2} =1$

I've using the form:

$\displaystyle b^2x^x + a^2y^2 = a^2b^2$

and setting:

$\displaystyle a^2b^2 = -4x$

But, nothing came good out of that.

Any suggestions?