#### Answer

$(x-2)^2+(y+1)^2=9$
Refer to the graph below.

#### Work Step by Step

RECALL:
A circle whose equation is of the form $(x-h)^2+(y-k)^2=r^2$ has its center at $(h, k)$ and has a radius of $r$.
The given circle has its center $(2, -1)$ and a radius of $3$ units.
Substituting these values into the equation above gives:
$(x-2)^2+(y-(-1))^2=3^2
\\(x-2)^2+(y+1)^2=9$
Refer to the graph in the answer part above.