括号负3a的平方b3次方的平方乘以括号负6分之一abc除以括号2分之一ab方的平方
=(-3a^2b^3)^2*(-1/6abc)/(1/2ab^2)^2
=(9a^4b^6)*(-1/6abc)/(1/4a^2b^4)
=(-3/2a^5b^7c)/(1/4a^2b^4)
=-6a^3b^3c