Write an equation of the circle with center (2, -9) and radius 3.

Answer:
[tex]c = {g}^{2} + {f}^{2} + {r}^{2} \\ c = {2}^{2} + {( - 9)}^{2} + {3}^{2} \\ c = 94 \\ = > \: {x}^{2} + {y}^{2} - 4x + 18y + 94 = 0[/tex]