1/(x+1) - 1/(x-1) .............combine fractions using the lcm as the product of the 2 denominators.

=...(x - 1) - (x + 1)

...----------------- ........do you know how to complete the numerator for this step?

......(x - 1)(x + 1)

=...x - 1 - x - 1

...--------------

.......(x^2 - 1)

=.........-2

......------------

........(x^2 - 1)

=...-1...................-2

....----.....x....------------ i'm essentially multiplying by 1 here so no change

.....-1..............(x^2 - 1)

=...........2

......------------

........(1 - x^2)