# How do you solve 3x^2 + 18x + 15 = 0 by completing the square?

Divide both sides of the equation by 3, which yields ${x}^{2} + 6 x + 5 = 0$. Add 4 to both sides of the equation, which yields ${x}^{2} + 6 x + 9 = 4$. This is done to make the left side ${\left(x + 3\right)}^{2}$. Taking the square root of both sides yields $x + 3 = 2$. Hence, $x = - 1$.