# How do you solve by completing the square x^2+8x=9?

${x}^{2} + 8 x - 9 = 0$
$\left({x}^{2} + 8 x + {\left(\frac{8}{2}\right)}^{2} - {\left(\frac{8}{2}\right)}^{2}\right) - 9 = 0$
$\left({x}^{2} + 8 x + 16 - 16\right) - 9 = 0$
$\left({x}^{2} + 8 x + 16\right) - 16 - 9 = 0$
${\left(x + 4\right)}^{2} - 25 = 0$