Alright so,
Rearragnge the equation to better see what to do! x^2 + 4x + y^2 - 2y = -1
Now, complete the square for x^2 + 4x
to: x^2 + 4x + 4 - 4 Remember, this is done by using \left (\frac{b}{2} \right )^2
Do the same with y^2 -2y
You'll get
(x +2)^2 + (y -1)^2 - 5 = -1
Which is (x +2)^2 +...