通分:4/3abc²与a-1/a²-9

问题描述:

通分:4/3abc²与a-1/a²-9

公分母:3abc²(a²-9),
4/(3abc²)=4(a²-9)/[3abc²(a²-9)]
(a-1)/(a²-9)=3abc²(a-1)/[3abc²(a²-9)].