Please help me solve for the value of x

Mr. walker gave his class the function f(x) = (x + 3)(x + 5). four students made a claim about the function. each student’s claim is below. jeremiah: the y-intercept is at (15, 0). lindsay: the x-intercepts are at (–3, 0) and (5, 0). stephen: the vertex is at (–4, –1). alexis: the midpoint between the x-intercepts is at (4, 0). which student’s claim about the function is correct?

1. what is the formula for finding the vertical distance between two points on a coordinate plane?

Find the roots of the polynomial function f(x) = x^3 + 2x^2 + x