(1/3x⁻¹y²)⁻²=(1/3)⁻²*x²y⁻⁴=9x² / y⁴
(3x⁻¹ / 4y⁻²)⁻¹ * 6xy² = (3y² / 4x)⁻¹ * 6xy² = 6xy²*4x/3y² =8x²
4) 3⁻⁹9⁻⁴ / 27⁻⁶ = 27⁶/3⁹*9⁴ =3⁶*9⁶ / 3⁹*9⁴ =9² / 3³ = 3⁴/3³=3
5) (4,6*10⁴)(2,5*10⁻⁵)= 4,6*2,5*10⁻¹= 11,5/10=1,15
6)(a⁻¹+b⁻¹)(a+b)⁻¹=(1/a+1/b) / (a+b) = (a+b)/ab : (a+b) =(a+b)/ab * 1/(a+b) = 1/(a+b)