Question

What is the line of symmetry for the parabola whose equation is y = x^2 - 12x + 7?

x=12?

Answer 1

just put your equation in wolfram alpha...
answer is:
x=6
http://www.wolframalpha.com/input/?i=y%3Dx^2-12x%2B7
and here is link to wolfram alpha...
http://www.wolframalpha.com/

Answer 2

you can write this as
\[\Large y=(x-6)^2-29\]
so line of symmetry should be
x=6