Question

What number would u add to complete the square ? x^2+22x=9

Answer 1

To complete the square, take half of the coefficient of x, 22, square it, then add it to both sides of the equation.

$x^2 + 22x = 9$

22 / 2 = 11
$11^2$ = 121

$x^2 + 22x + 121 = 9 + 121$
$x^2 + 22x + 121 = 130$

Then you can go from there.