Decades: 760s 770s 780s 790s 800s - 810s - 820s 830s 840s 850s 860s
Years: 814 815 816 817 818 - 819 - 820 821 822 823 824
Births
Deaths
... by a, we have <math> x^2 + \left( \frac{b}{a} \right) x + \frac{c}{a}=0 </math> which is equivalen ...