Completing the Square by Boxed Rockets

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

x^{2} - 15 x - 4

{(x - \frac{15}{2})}^{2} - \frac{241}{4}

x^{2} + 11 x - 2

{(x + \frac{11}{2})}^{2} - \frac{129}{4}

x^{2} + 5 x - 10

{(x + \frac{5}{2})}^{2} - \frac{65}{4}

x^{2} + 6 x + 6

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

x^{2} - 6 x + 4

{(x - 3)}^{2} - 5

x^{2} - 8 x + 9

{(x - 4)}^{2} - 7