3. Преобразуйте выражение: a) ((2/3)a⁻⁴b⁻²)⁻²; б) ((5a⁻²/6b⁻¹))⁻²×10a³b⁴.

a) ((2/3)a⁻⁴b⁻²)⁻² = (2/3)⁻² × a^(-4×(-2)) × b^(-2×(-2)) = (3/2)² × a⁸ × b⁴ = (9/4)a⁸b⁴

б) ((5a⁻²/6b⁻¹))⁻²×10a³b⁴ = (5/6)⁻² × a^(-2×(-2)) × b^(-1×(-2)) × 10a³b⁴ = (6/5)² × a⁴ × b² × 10a³b⁴ = (36/25) × 10 × a^(4+3) × b^(2+4) = (360/25)a⁷b⁶ = (72/5)a⁷b⁶

Ответ: a) (9/4)a⁸b⁴; б) (72/5)a⁷b⁶