Centuries: 6th century - 7th century - 8th century
Decades: 640s 650s 660s 670s 680s - 690s - 700s 710s 720s 730s 740s
Years: 691 692 693 694 695 696 697 698 699 700 701
Births
Deaths
... b/(2a) 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> ...