Question 1019845
{{{(2n+1)^3}}} expands to {{{8n^3 + 12n^2 +6n + 1}}}
{{{(2n11)^3}}} expands to {{{8n^3 - 12n^2 +6n - 1}}}
So {{{ (2n+1)^3-(2n-1)^3 }}} =
{{{8n^3 + 12n^2 +6n + 1}}} - {{{8n^3 - 12n^2 +6n - 1}}}
= {{{24n^2 + 2 }}}
Check the answer using www.wolframalpha.com