Question

How do you evaluate a function `f(x)=x+7` for a specific value, f(5)?

Answer 1

`f(5)=12`

Explanation:

`color(blue)x` is just a "place-holder" or "variable.

If `fcolor(blue)(x)=color(blue)x+7`
then (using a different variable) `f(color(blue)t)=color(blue)t+5`
or
using a constant `f(color(blue)x)=color(blue)5+7`

Since `5+7=12`
for the given example `f(5)=12`