Write the Quadratic Function in Vertex Form $$y = x ^ { 2 } - 20 x + 91$$

Multiple Choice

Write the quadratic function in vertex form.
- $$y = x ^ { 2 } - 20 x + 91$$

A) $y = ( x + 10 ) ^ { 2 } + 9$
B) $y = ( x + 10 ) ^ { 2 } - 9$
C) $y = ( x - 10 ) ^ { 2 } + 9$
D) $y = ( x - 10 ) ^ { 2 } - 9$