+21 1. The vertex of a parabola is at (12, -4), and its axis of symmetry is vertical. One of the x-intercepts is at (15, 0). What is the x-coordinate of the other x-intercept
2. The graph of the equation \(y =ax^2 + bx + c \), where a, b, and c are constants, is a parabola with an axis of symmetry \(x = -3\). Find \(\frac{b}{a}\).
