Set 7: Quadratic Equations (Advanced)

Choice B is correct. Choice B is the correct answer. This equation can be solved by factoring out the Greatest Common Factor (GCF). 1. Identify the GCF of $x^2$ and $-4 x$, which is $x$. 2. Factor out $x$: $x(x - 4) = 0$. 3. Set each factor to zero: $x = 0$ or $x - 4 = 0$. 4. Solve: $x = 0$ or $x = 4$. Choice A is incorrect because it misses the solution $x=0$. Dividing both sides by $x$ is invalid because $x$ could be zero. Choice C is incorrect because $x-4=0$ gives $x=4$, not -4. Choice D is incorrect because this would be the solution for $x^2 - 4 = 0$ (Difference of Squares).