Question

What ia the value of f(a) if f(x)=3x-2?

Answer 1

`f(a)=3a-2`

Explanation:

If `f(color(red)x)=3color(red)x-2`
then
`color(white)("XXX")f(color(blue)a)`
is simply `f(color(red)x)` with `color(red)x` replaced by `color(blue)a`

`color(white)("XXX")f(cancel(color(red)x)^color(blue)a)=3cancel(color(red)x)^color(blue)a-2`
`color(white)("XXXXXXX")=3color(blue)a-2`

For a more concrete example, you might evaluate `f(color(magenta)6)` for the same definition of `f(color(red)x)`
`color(white)("XXX")f(cancel(color(red)x)^color(magenta)6)=3 * cancel(color(red)x)^color(magenta)6-2`

`color(white)("XXX")f(color(magenta)6)=3 * color(magenta)6-2=18-2=16`