Tamworth castle is one of the best preserved Norman Motte-and-Bailey Castles[?] in Britain, and was first built after the Norman Invasion of Britain in the 11th century.
... square roots of both sides yields <math>x+\frac{b}{2a}=\frac{\pm\sqrt{b^2-4ac}}{2a}.</math> Subtracting b/(2a) from both sides, w ...