The twenty-second century comprises the years 2101-2200. This is different from the century known as the twenty-one hundreds, which comprises the years 2100-2199.
... from both sides, we get
<math>x=\frac{-b}{2a}\pm\frac{\sqrt{b^2-4ac}}{2a}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}.</math>
Generalizations
The formula and ...