Answer:
f(x) = 3x + 9: y - intercept is option c. (0,-9)
f(x) = 3x - 9: y - intercept is option b. (0, 9)
Explanation:
option a and d cant be correct since y = 0 in those answer when the y - intercept is when x = 0
If the function f(x) = 3x + 9
than x = 0
f(x) = 3(0) + 9
f(x) = 0 + 9
f(x) = 9
x = 0 and y = 9 (0, 9)
If the function f(x) = 3x - 9
than x = 0
f(x) = 3(0) - 9
f(x) = 0 - 9
f(x) = -9
x = 0 and y = -9 (0, -9)