Answer:
b = -12
Step-by-step explanation:
The axis of symmetry goes through the point that represents the x value of the vertex when you complete the square.
y = (x - 6)^2 + 10 + c
y = x^2 - 12x + 36 + 10 - 36
y = (x^2 - 12x + 36) - 26
y = (x - 6)^2 - 26
