Set 9: Quadratic Equations (Advanced)

Choice B is correct. Choice B is the correct answer. Discriminant: $\Delta = 16 - 16 = 0$. When $\Delta = 0$, there's exactly one repeated real solution. Factor: $x^2 - 4 x + 4 = (x - 2)^2 = 0$, so $x = 2$ (repeated). Choice A is incorrect because $\Delta = 0$ means one solution exists. Choice C is incorrect because two distinct solutions require $\Delta > 0$. Choice D is incorrect because quadratics never have three solutions.