Answer the following quadratic function

f(x)= x^2 + 6x - 16
a)What is the vertex (h,k)of f?
b)What is the axis of symmetry?
c)What are the intercepts?

2 answers

x^2 + 6x - 16 = (x+3)^2 - 25 = (x+8)(x-2)
that should get you started.
2,-8 is your answer