Question: 9. The graph of the linear function $f$ passes through the points $(1,-9)$ and $(-3,3)$.\n\nThe linear equation has a slope of $-3$ and a zero of $-4$.\nThe linear equation has a slope of $3$ and a zero of $-4$.\nThe linear equation has a slope of $-3$ and a zero of $-2$.\nThe linear equation has a slope of $3$ and a zero of $-2$.\n\nWhich statement about the linear function is true?

1. **State the problem:** We are given two points $(1,-9)$ and $(-3,3)$ on the graph of a linear function $f$. We need to find the slope and the zero (root) of the linear function and determine which statement about the function is true.\n\n2. **Find the slope $m$ of the line passing through the points:**\n\n$$m = \frac{y_2 - y_1}{x_2 - x_1} = \frac{3 - (-9)}{-3 - 1} = \frac{3 + 9}{-4} = \frac{12}{-4} = -3$$\n\n3. **Write the equation of the line in point-slope form:**\n\nUsing point $(1,-9)$,\n$$y - (-9) = -3(x - 1)$$\n$$y + 9 = -3x + 3$$\n$$y = -3x + 3 - 9$$\n$$y = -3x - 6$$\n\n4. **Find the zero of the function (where $y=0$):**\n\nSet $y=0$:\n$$0 = -3x - 6$$\n$$3x = -6$$\n$$x = \frac{-6}{3} = -2$$\n\n5. **Interpretation:** The slope is $-3$ and the zero is $-2$.\n\n6. **Conclusion:** The correct statement is: "The linear equation has a slope of $-3$ and a zero of $-2$."