Question

Suppose the equation of the axis of symmetry for a quadratic function is x = -3 and one of the x-intercepts is -8. What is the other x-intercept?

Answer 1

let's notice, if the axis of rotation is at x = -3, or namely the x-coordinate of the vertex is at -3, and one of the x-intercepts is at x = -8, that's 5 units of distance to the left, the other x-intercept is also 5 units of distance, but to the right of the axis of rotation. Check the picture below.