(10n + 1)(10n - 1)
These binomials were factored out from the expression given by difference of squares. If you multiply the binomials and combine all like terms, it would equal 100n^2 - 1.
(10n + 1)(10n - 1)
100n^2 - 10n + 10n - 1
100n^2 - 1
Hope this helps!