Set 12: Quadratic Equations (Intermediate)

Choice B is correct. Choice B is the correct answer. A perfect square trinomial fits the form $x^2 \pm 2 bx + b^2$. The constant term must be the square of half the linear coefficient. 1. For $x^2 - 6 x + 9$: Half of -6 is -3. $(-3)^2 = 9$. This matches. 2. It factors to $(x - 3)^2$. Choice A is incorrect because $5^2 = 25 \neq 20$. Choice C is incorrect because $2^2 = 4 \neq 16$. Choice D is incorrect because the constant term in a perfect square trinomial must be positive (a real number squared is always positive).