## Algebra 2 (1st Edition)

$c=49$ $(x+7)^{2}$
$x^{2}+14x+c\qquad$ ... find half the coefficient of $x$. $\displaystyle \frac{14}{2}=7$ $\qquad$ ...square the result. $7^{2}=49\qquad$ ...replace $c$ with $49$ in the original expression The trinomial $x^{2}+14x+c$ is a perfect square when $c=49.$ Then $x^{2}+14x+49=(x+7)(x+7)=(x+7)^{2}$