Respuesta :

I'm not sure what you mean by a.
In a square (x-c)(x-c)= x^2 -2cx + c^2
-2cx = -12x, c = 6
(x-6)(x-6) = x^2-12x + 7 + (36-7) = x^2-12x+7 + 29 = x^2 - 12x + 36
I think a is probably either -6 or 29.