Whenever you complete a square, you're really taking this:
(x+b)^2=x^2+2bx+b^2 [/tex]
And equating roots. Here, the b is clearly 11 (2b=22 implies b=11), so that means we want 121 as our ending number. That means we should add 121 to both sides to get:
[tex] x^2+22x+121=9+121 \implies \\
(x+11)^2=130 [/tex]
