Solve the Equation by Completing the Square $$x ^ { 2 } + 6 x = 31$$

Multiple Choice

Solve the equation by completing the square. Express any complex numbers using i notation.
- $$x ^ { 2 } + 6 x = 31$$

A) $x = - 3 \pm 2 \sqrt { 10 }$
B) $x = - 3 \pm 2 \sqrt { 20 }$
C) $x = 2 \sqrt { 10 } \pm 3$
D) $x = \pm 2 \sqrt { 10 }$