9*(4/9-X)=7/9

问题描述:

9*(4/9-X)=7/9

9×(4/9-x)=7/9
4/9-x=7/9 ÷ 9
4/9-x=7/81
x=4/9 - 7/81
x=36/81 - 7/81
x=29/81