Which is the equation of a hyperbola with directrices at x = ±3 and foci at (4, 0) and (−4, 0)? x squared over 16 minus y squared over 4 equals 1 x squared over 12 minus y squared over 4 equals 1 y squared over 16 minus x squared over 4 equals 1 y squared over 12 minus x squared over 4 equals 1