Question Number 163865 by mathlove last updated on 11/Jan/22
Answered by TheSupreme last updated on 11/Jan/22
$${x}\neq\pm\mathrm{1} \\ $$$$ \\ $$
Commented by mr W last updated on 11/Jan/22
$${why}\:{not}\:\pm\mathrm{1}? \\ $$
Answered by mahdipoor last updated on 11/Jan/22
$${if}\:\frac{{a}}{{b}}>\mathrm{0}\:\Rightarrow\:{ab}>\mathrm{0} \\ $$$$\Rightarrow\mid{x}−\mathrm{1}\mid+\mid{x}+\mathrm{1}\mid>\mathrm{2}>\mathrm{0}\:\Rightarrow\:\forall{x}\in{R} \\ $$