Question

find the radius of the circle.
3(x - 5)^{2}+3(y + 9)^{2}=48
radius = ?

Explanation:

Step1: Divide both sides by 3

$$\begin{align*} \frac{3(x - 5)^2+3(y + 9)^2}{3}&=\frac{48}{3}\\ (x - 5)^2+(y + 9)^2&=16 \end{align*}$$

Step2: Compare with the standard circle equation

The standard form of a circle equation is $(x - a)^2+(y - b)^2=r^2$, where $r$ is the radius.
Here $r^2 = 16$, so $r=\sqrt{16}$

Answer:

$4$