What is the domain of f/g, given f(x)= x+2 and g(x)= x-7?

Question

I was told this below,
all real numbers EXCEPT 7

But
My choices are this,
(-infinity,7) U (7,infinity)
(-infinity,-7) U (-7,infinity)
(-infinity,-2) U (-2,7)U (7,infinity)
(-infinity,infinity)

Answer 1

well, yeah.
(-∞,∞) is all real numbers.

So, how do you get x=7 out of there? You divide it up into two intervals, each excluding x=7

So, whaddaya think?

Answer 2

there is something about the shape of the parentheses/brackets that excludes one end of an interval

sorry...rusty on this part

Answer 3

Is it A then steve??

Answer 4

that is correct. The () interval notation indicates that the endpoints are not included.