Set 16: Linear Functions (Advanced)

Choice A is correct. Choice A is the correct answer. Check the coordinates. 1. Observe: Both points have an x-coordinate of 1. 2. Conclusion: Since $x$ is always 1, the equation is $x = 1$. This is a vertical line. 3. Slope Check: $\frac{-5 - 3}{1 - 1} = \frac{-8}{0}$ (Undefined), confirming it's vertical. Strategic Tip: If the x-coordinates are the same, it's $x = k$. If y-coordinates are the same, it's $y = k$. Choice B is incorrect because $y$ values change. Choice C is incorrect because it only fits one point. Choice D is incorrect because x is 1, not 3.