Question

R f(x)
--2-1
-11-3
0-5
1-7
Which function rule defines f(x)?

Answer 1

B. f(x) = -2x - 5

Explanation:

✔️Find the rate of change:

Rate of change using two of the given pair, say (0, -5) and (1, -7)

Rate of change (m) = ∆f(x) / ∆x = (-7 -(-5)) / (1 - 0) = -2/1 = -2

✔️Find y-intercept (b):

y-intercept (b) = -5 because the y-intercept is the value of f(x) when x = 0.

✔️Substitute m = -2 and b = -5 into f(x) = mx + b

Thus,

f(x) = -2x + (-5)

f(x) = -2x - 5