f(x)=1-3x when f(x)-f(1)/x-1

To find the value of (f(x) - f(1))/(x - 1) for the given function f(x) = 1 - 3x, we need to substitute the values into the equation.

First, let's find f(1):
f(1) = 1 - 3(1)
f(1) = 1 - 3
f(1) = -2

Now, let's substitute these values into the expression (f(x) - f(1))/(x - 1):
(f(x) - f(1))/(x - 1) = [1 - 3x - (-2)]/(x - 1)

Simplifying further:
(f(x) - f(1))/(x - 1) = (1 - 3x + 2)/(x - 1)
= (-3x + 3)/(x - 1)

Therefore, the expression (f(x) - f(1))/(x - 1) for the given function f(x) = 1 - 3x is (-3x + 3)/(x - 1).