Question Number 153817 by eman_64 last updated on 10/Sep/21
Commented by puissant last updated on 10/Sep/21
$${Correct}..! \\ $$
Commented by alisiao last updated on 10/Sep/21
$$\boldsymbol{{yes}}\:\boldsymbol{{it}}\:\boldsymbol{{is}}\:\boldsymbol{{very}}\:\boldsymbol{{easy}}\: \\ $$$$ \\ $$$$!\boldsymbol{{n}}\:=\:\boldsymbol{{n}}!\:×\:\left(−\mathrm{1}\right)^{\boldsymbol{{n}}} \:×\:\frac{\mathrm{1}}{\boldsymbol{{n}}!} \\ $$
Commented by puissant last updated on 11/Sep/21
$${Sir}\:!{n}=\:{n}!×\underset{{k}=\mathrm{0}} {\overset{{n}} {\sum}}\left(−\mathrm{1}\right)^{{k}} ×\frac{\mathrm{1}}{{k}!}.. \\ $$