When you have compound (complex?) fractions like you have in 1 what you need to do is clear the fractions in both the numerator and denominator.

1. You need to multiply the numerator and denominator by x^2 - 1 to clear the fraction in the numerator. Then you need to multiply the numerator and denominator by x+1 to clear the fraction in the denominator. You then get:

[x^3(x + 1)]/[x^5(x^2 - 1)] = (x + 1)/[x^2(x^2 - 1)] = (x + 1)/[x^2(x + 1)(x - 1)] = 1/[x^2(x - 1)]

See if you can get the rest. Here are what I got:

2. (x - 1)/x^2

3. x^2(x - 1)

4. x^2/(x - 1)

-Dan