Completing the Square by Boxed Rockets

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

x^{2} + 15 x - 7

{(x + \frac{15}{2})}^{2} - \frac{253}{4}

x^{2} + 15 x - 7

{(x + \frac{15}{2})}^{2} - \frac{253}{4}

x^{2} - 6 x - 4

{(x - 3)}^{2} - 13

x^{2} + x + 7

{(x + \frac{1}{2})}^{2} + \frac{27}{4}

x^{2} - 11 x - 7

{(x - \frac{11}{2})}^{2} - \frac{149}{4}

x^{2} - 8 x - 3

{(x - 4)}^{2} - 19