Answer:

Step-by-step explanation:
Answer:
I don't really know so sorry about that.
Step-by-step explanation:
Answer:
(
−
∞
,
∞
) {
x
|
x
∈
R
}
Step-by-step explanation:
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.
They're called variables (this sounds like vary because the number that a letter could represent varies) so when i say 1 + x = 3 it is saying that they don't know the value of x yet but of course you can solve that by subtracting 1 from 3 which is 2