Answer:
Step-by-step explanation:
y = -x^2 + 6x - 17
y = -(x^2 - 6x) - 17
y = -(x^2 - 6x + 9 - 9) - 17
y = -(x^2 - 6x + 9) - 17 + 9
y = -(x - 3)^2 - 8
The maximum value is -8 for x = 3.
