Respuesta :

Answer:

-7

Step-by-step explanation:

f(x) = -(x+7)^2 -10

This parabola is written in the form

y = a(x-h)^2+k

Where (h,k) is the vertex

f(x) = -(x+7)^2 -10 = (-(x- -7)^2 + -10

The vertex is at (-7, -10)

The x coordinate is -7