Question Number 123638 by 676597498 last updated on 26/Nov/20
$$\mathrm{show}\:\mathrm{that}\:\mathrm{if}\:\mathrm{x}\in\mathbb{R}\:\mathrm{then}\:\mathrm{x}\:\mathrm{and}\:−\mathrm{x}\:\mathrm{cannot}\:\mathrm{be}\:\mathrm{positive} \\ $$
Commented by talminator2856791 last updated on 27/Nov/20
$$\:\mathrm{this}\:\mathrm{is}\:\mathrm{just}\:\mathrm{a}\:\mathrm{rule} \\ $$