Answer:
x>-1
Step-by-step explanation:

notice, there are three terms, therefore is a
trinomial.
the term that has the highest degree, has a degree of 3, therefore the degree of the polynomial as a whole is 3, or a
cubic degree.
so, is a
cubic trinomial.
Using the shortcut for binomial expansion, which still took 45 minutes, I got 23-26. The coefficient on the x^6 term is 34,020; the coefficient on the x^4 term is -495; on the x^7 term it's 1800; on the x^3 term it's 337,920. I'm pooped. The rest is factorial notation, kinda the same thing, but...