Question

How do you evaluate the function `f(x)=6x` when x=3?

Answer 1

Substitute `color(red)(3)` for `color(red)(x)` in `f(x)` and calculate the result:

`f(color(red)(x)) = 6color(red)(x)` becomes:

`f(color(red)(3)) = 6 xx color(red)(3)`

`f(color(red)(3)) = 18`