Answer
$x=-2$
Work Step by Step
The coefficient of x is 6.
Adding the square of half the coefficient of x creates a perfect square.
$(6\div2)^2=3^2=9$
$x^2+6x=-8$
Add the square of half the coefficient of x to each side of the equation.
$x^2+6x+9=-8+9$
Simplify.
$x^2+6x+9=1$
Factor the polynomial.
$(x+3)^2=1$
Take the square root of each side.
$\sqrt{(x+3)^2}=\sqrt 1$
Simplify.
$x+3=1$
Subtract 3 from each side.
$x+3-3=1-3$
Simplify.
$x=-2$
