Strictly speaking this entry is about communities like villages, towns and cities that do not exist in the world we know. Like fictional countries, most fictional cities resemble either a specific place or present one version of archetypal place.
... we add the square of b/(2a) to both sides, getting
<math>x^2+\frac{b}{a}x+\frac{b^2}{4a^2}=-\frac{c}{a}+\frac{b^2}{4a^2}.</math>
The left side is now a ...