The function `f(x) = y= -3x + 4` .

Isolate x and express it in terms of y.

`y= -3x + 4`

=> `-3x = y - 4`

=> `x = (4 - y)/3`

=> `f^-1(x) = (4 - x)/3`

**The domain and range of `f^-1(x)` is the set of real numbers R.**

The function `f(x) = y= -3x + 4` .

Isolate x and express it in terms of y.

`y= -3x + 4`

=> `-3x = y - 4`

=> `x = (4 - y)/3`

=> `f^-1(x) = (4 - x)/3`

**The domain and range of `f^-1(x)` is the set of real numbers R.**