(3/4a^4b^7+1/2a^3b^8-1/9a^2b^6)/(-1/3ab^3)^2计算

问题描述:

(3/4a^4b^7+1/2a^3b^8-1/9a^2b^6)/(-1/3ab^3)^2
计算

27/4a^2b+9/2ab^2-1