Bonjour,
1) D = a⁴ × b² × c⁻³ × a⁻² = a⁴⁺⁽⁻²⁾ × b² × c⁻³ = a² × b² × c⁻³ = (ab)² × c⁻³ = (ab)²/c³
E = (a³ × b⁵ × c) / (a² × b⁷) = a³⁻² × b⁵⁻⁷ × c = a × b⁻² × c = ac × 1/b² = ac/b²
2) si a=-4, b=1 et c=2
alors D = (-4×1)²/2³ = 16/8 = 2
et E = (-4 × 2)/1² = -8
