Answer:
x = -1
Step-by-step explanation:
In a parabola with an equation equal to:
f(x) = ax² + bx + c
The equation of the axis of symmetry is x = -b/2a
So, if we have the equation:
f(x) = x² + 2x - 15
The value of a is 1, the value of b is 2, and the value of c is -15.
Therefore, the equation of the axis of symmetry is:
x = -2/(2*1) = -2/2 = -1
So, the answer is x = -1