Choice A is the correct answer. In the slope-intercept form $y = mx + b$, $m$ is the slope and $b$ is the y-intercept.

1. Identify: Compare $y = -3x + 7$ with $y = mx + b$.
2. Match: The coefficient of $x$ is $-3$, so $m = -3$. The constant term is $7$, so $b = 7$.

💡 Strategic Tip: The number attached to $x$ is always the slope (rate of change), and the lonely number is the y-intercept (starting value).

Choice B is incorrect because it swaps the slope and y-intercept. Choice C is incorrect because it ignores the negative sign of the slope. Choice D is incorrect because it changes the sign of the y-intercept.