Question

Write the equation in standard form for the circle x² + y²- 18y - 19 = 0.

Answer 1

$\begin{gathered} x^2+y^2-18y-19=0 \\ x^2+(y^2-18y+81)-81-19=0 \\ x^2+(y-9)^2=100 \\ (x-0)^2+(y-9)^2=10^2 \end{gathered}$