ANSWER:
Domain: (-∞, ∞)
STEP-BY-STEP EXPLANATION:
We have the following function:
[tex]f(x)=-\:9x+2\:[/tex]The domain of a function is the set of all possible input values of the function. In this case, it would be the interval of values that x can take.
In this function, x can take any value in real numbers.
Therefore, in that case, it will be:
[tex]D=(-\infty,\infty)[/tex]