Question

What is the axis of symmetry of y = x2 + 9 + 8x?

Select one:
a. x = -7
b. x = 7
c. y = 4
d. x = -4

Answer 1

is it D?

Answer 2

Use
$$
y=ax^2+bx+c\\
y=-\cfrac{b}{2a}
$$
Where a=1 and b=8

This comes from the quadratic formula.