Complete the square to change into standard form

Question

Here is the equation:

$x^2 + y^2 + 4x - 6y - 3 = 0$

Here are the instructions:

Complete the square to change the equation info standard form. Then graph the equation.

Because both $y^2$ and $x^2$ are present, I do not know what to do. Thank you!

Answer 1

$$\begin{align}x^2+y^2+4x-6y-3=0&\iff x^2+2\cdot 2x+2^2-2^2+y^2-2\cdot 3y+3^2-3^2-3=0\\&\iff (x^2+4x+4)+(y^2-6y+9)=3+4+9\\&\iff (x+2)^2+(y-3)^2=4^2.\end{align}$$