Question

If f is a linear function where f(-1) = 4 and f(5)=1, find a formula for f(x).

Answer 1

Answer:

f(x) = -0.5x + 3.5

Step-by-step explanation:

f(x) = mx + b

f(-1) = -m + b = 4   ...(1)

f(5) = 5m + b = 1   ...(2)

(1)-(2):  -6m = 3         m = -1/2    (-0.5)

b = 4 + (-1/2) = 3.5

Equation: f(x) = -0.5x + 3.5