# How do you complete the square for x^2+8x?

May 15, 2018

${x}^{2} + 8 x + 16$
$\text{since the coefficient of the "x^2" term is 1}$
$\text{add "(1/2"coefficient of the x-term")^2" to}$
${x}^{2} + 8 x$
$\Rightarrow {x}^{2} + 8 x {\textcolor{red}{+ 4}}^{2} = {x}^{2} + 8 x + 16 = {\left(x + 4\right)}^{2}$