Completing the Square by Boxed Rockets

Solve Using Completing the Square.

x^{2} - 12 x + 6 = 0

x = 6 \pm \sqrt{30}

x^{2} + 6 x - 2 = 0

x = -3 \pm \sqrt{11}

x^{2} + 14 x + 7 = 0

x = -7 \pm \sqrt{42}

x^{2} - 6 x - 3 = 0

x = 3 \pm 2 \sqrt{3}

x^{2} + 8 x + 9 = 0

x = -4 \pm \sqrt{7}

x^{2} - 12 x + 5 = 0

x = 6 \pm \sqrt{31}