Question

The graph of linear function f passes through the point (1, -9) and has a slope of -3. What is the zero of f ?

Answer:
A.) 2
B.) 4
C.) -6
D.) -2​

Answer 1

D. -2

Explanation:

Answer 2

-2

Explanation:

The standard equation of a line is y = mx+c

m is the slope

c is the intercept

Given

Slope = -3

Get the intercept c;

Substitute m = -3 and (1, -9) into y = mx+c

-9 = -3(1) + c

-9 = -3 + c

c = -9 + 3

c = -6

The equation becomes

y = -3x + (-6)

y = -3x-6

f(x) = -3x-6

The zero of f occurs at f(x) = 0

0 = -3x-6

3x = -6

x = -6/3

x = -2

Hence the zero of the function is -2