(-3*a^1/2*b^1/3)÷(1/3*a^1/6*b^5/6)
=((-3÷1/3)(a^1/2÷a^1/6)(b^1/3÷b^5/6)
=-9a^(1/2-1/3)b^(1/3-5/6)
=-9a^(1/6)b^(-1/2)