Bonjour,
27 × 9⁵ = 3³ × (3²)⁵ = 3³ × 3²ˣ⁵ = 3³⁺¹⁰ = 3¹³
(81⁴ × 9⁻²)/27⁻³ = ((3⁴)⁴ × (3²)⁻²)/(3³)⁻³
= (3⁴ˣ⁴ × 3²ˣ⁽⁻²⁾) / 3³ˣ⁽⁻³⁾
= (3¹⁶ × 3⁻⁴)/ 3⁻⁹
= (3¹⁶⁺⁽⁻⁴⁾)/3⁻⁹
= 3¹²/3⁻⁹
= 3¹²⁻⁽⁻⁹⁾
= 3²¹
9⁻³ × 81² = (3²)⁻³ × (3⁴)²
= 3²ˣ⁽⁻³⁾ × 3⁴ˣ²
= 3⁻⁶ × 3⁸
= 3⁻⁶⁺⁸
= 3²
