3. Вычислить 5⁻³.5⁻⁹ / 5⁻¹¹

(5⁻³ * 5⁻⁹) / 5⁻¹¹ = 5⁻¹² / 5⁻¹¹ = 5⁻¹²⁻⁽⁻¹¹⁾ = 5⁻¹²⁺¹¹ = 5⁻¹ = 1/5