Centuries: 9th century - 10th century - 11th century
Decades: 870s 880s 890s 900s 910s - 920s - 930s 940s 950s 960s 970s
Years: 917 918 919 920 921 - 922 - 923 924 925 926 927
Births
Deaths
... our quadratic equation by a, we have <math> x^2 + \left( \frac{b}{a} \right) x + \frac{c}{a}=0 </math> which is equivalen ...