f(x)=9x+7

Question

The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression undefined.

help why is the answer negative infinity, infinity?

thank you so much...please explain in plain terms (aka baby words...lol) thanks

Answer 1

the description of the domain is all real numbers.

The interval where f(x) is defined is (-∞,∞) -- that is, all real numbers.

Answer 2

domain is a allowable x. In this case, those numbers range from neg inf to positive inf, ie, all real numbers.