1. The graph of the equation y=ax^2 + bx + c, where a, b, and c are constants, is a parabola with axis of symmetry x = -3. Find b/a
2. 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?