Question Number 145285 by SinNombre last updated on 03/Jul/21
$${x}=\mathrm{2}−\mathrm{2}+\mathrm{2}−\mathrm{2}+\mathrm{2}−\ldots+\mathrm{2}−\mathrm{2}+\mathrm{2}=\mathrm{2} \\ $$
Commented by phally last updated on 04/Jul/21
$$\mathrm{x}_{\mathrm{1}} =\mathrm{2}+\mathrm{2}+\mathrm{2}+…+\mathrm{2}\:\left\{\mathrm{n}+\mathrm{1}\right\} \\ $$$$\mathrm{x}_{\mathrm{2}} =−\left(\mathrm{2}+\mathrm{2}+\mathrm{2}+…\mathrm{2}\right)\left\{{n}\right\} \\ $$$$\Rightarrow\mathrm{x}_{\mathrm{1}} +\mathrm{x}_{\mathrm{2}} =\mathrm{2} \\ $$