Final answer:
The zero of a linear function with a slope of -3 passing through the point (1, -9) is x = 2. Since this value is not listed in the choices, there might be an error in the question or answer options.
Step-by-step explanation:
The student wants to find the zero of a linear function f, which has a slope of -3 and passes through the point (1, -9). To find the zero of the function, we need the x-value when y is equal to zero. We can use the point-slope form of a line equation which is (y - y1) = m(x - x1), where m is the slope and (x1, y1) is a known point on the line.
Applying the given point and slope, we have (y - (-9)) = -3(x - 1). To find the zero, set y to zero.
0 - (-9) = -3(x - 1)
=> 9 = -3(x - 1)
=> 9 = -3x + 3
=> 6 = -3x
=> x = -6/(-3)
=> x = 2
The zero of the function f is x = 2, which is not listed among the choices, suggesting there may be an error in the question or the choices provided.