F(x)=12x+3 what is the practical domain of the function?

We are given function: f(x) = 12x+3.

Generally we start x from 0 and we can take any number for x to get some real number of f(x).

Therefore, domain of the function start from 0.

And we can take any number 0 or greater than 0 to get some value of f(x).

So, we can say that domain of the function is " All real numbers greater than or equal to 0".

what is the original number? you forgot to add it.