posted by Anon .
x^3-x = x(x^2-1)
I don't get it...
sure you do. factor out x^2-1 top and bottom
but don't you have to get rid of the negative exponents somehow..?
sorry. I missed the negative exponents.
(x^-3 - x)/(x^(-2)-1)
(1 - x^4)/x^3 / (1-x^2)/x^2
(1-x^4)/x^3 * x^2/(1-x^2)
(1-x^2)(1+x^2) / x(1-x^2)
How did you go from the original question to the 1st step?
1/x^3 - x
over a common denominator of x^3, x = x^4/x^3
ohmygosh.. i'm an idiot.. thank you! you're the bestt!(: