Answer:
vertex = (- 5, - 13 )
Explanation:
given a quadratic in standard form : y = ax² + bx + c ( a ≠ 0 )
then the x- coordinate of the turning point ( vertex) is
x = -

y = x² + 10x + 12 ← is in standard form
with a = 1, b = 10 , then
x = -
= - 5
substitute x = - 5 into the equation and evaluate for y
y = (- 5)² + 10(- 5) + 12 = 25 - 50 + 12 = - 13
turning point = (- 5, - 13 )