Answer:
(C) -6
Step-by-step explanation:
Given the following data;
Points on the graph (x1, y1) = (1, -9).
Mathematically, the equation of a straight line is given by the formula;
y = mx + c
Where;
m is the slope.
x and y are the points
c is the intercept.
To find the zero of the linear function f, we would use the following formula;
y - y1 = m(x - x1)
Substituting into the formula, we have;
y - (-9) = -3(x - 1)
y + 9 = -3x + 3
y = -3x + 3 - 9
y = -3x -6 = mx + c
Intercept (c) or zero of a function = -6