First make sure the expression is correctly transcribed:
does not equal
I suspect it's the latter you need.
Because of the lack of typesetting capabilities, parentheses are required around the numerator and the denominator.
Hints for asymptotes and domains:
1. All polynomials have a domain of R, or (-∞,∞).
2. Horizontal asymptotes are finite values to which the function approaches when x→±∞.
3. Vertical asymptotes for a rational function (i.e. polynomials in both numerator and denominator) occur when the denominator equals zero.
4. The domain of a rational function is therefore (-∞,∞)-points at which vertical asymptotes occur.