Using the formula x = b/(-2a) to find the x of the vertex you can find y of the vertex and plug into y = a(x - h)² + k where (h, k) is the vertex
h = x = -6/(-2×1) = 3
k = y = (3)² - 6(3) + 7 = -2
a = 1 because it is the coefficient of x² in y = ax² + bx + c
Answer: y = (x - 3)² - 2
