How would you answer this question?

Question

Use completing the square to try and get the standard form equation below into vertex form.

Standard: f(x)=ax²+bx+c Vertex: f(x)=a(x-h)²+k

f(x)=x²+6x-7

Answer 1

f(x) = x² + 6x + 9 + 7 - 9

f(x) = (x + 3)² - 2