Answer:
b) x = - 1
Step-by-step explanation:
You want the equation of the axis of symmetry for a parabola with x-intercepts of 5 and -7.
Symmetry
The given x-intercepts are symmetrical about the axis of symmetry, so its x-intercept is the midpoint of the segment between (5, 0) and (-7, 0).
That midpoint is ...
((5, 0) +(-7, 0))/2 = (-2, 0)/2 = (-1, 0)
The vertical line through this point has equation ...
x = -1
