Pope Urban V makes the first attempt to move the Papacy back to Rome from Avignon. This move is reversed in 1370 when he is forced to return to Avignon and shortly afterwards dies.
... single fraction; the common denominator is 4a2. We get
<math>\left(x+\frac{b}{2a}\right)^2=\frac{-4ac+b^2}{4a^2}=\frac{b^2-4ac}{4a^2}.</math>
Taking ...