Completing the Square by Boxed Rockets

Write the following in the form ${(x + a)}^{2} + b$

x^{2} - 9 x - 6

{(x - \frac{9}{2})}^{2} - \frac{105}{4}

x^{2} + 13 x + 4

{(x + \frac{13}{2})}^{2} - \frac{153}{4}

x^{2} - 12 x - 5

{(x - 6)}^{2} - 41

x^{2} + 9 x - 8

{(x + \frac{9}{2})}^{2} - \frac{113}{4}

x^{2} + 6 x - 2

{(x + 3)}^{2} - 11

x^{2} + 4 x - 8

{(x + 2)}^{2} - 12