5/9x【9/5+18】; =5/9x9/行悔升档老5+5/9x18; =1+10; =11; 13/14-28分之15/前姿8分之5; =13/14-15/28x8/5; =13/14-6/7; =13/14-12/14; =1/14
5/9×﹙9/5+18﹚=5/9×9/5+5/9×18=1+10=1113/14-15/28÷5/8=13/14-15/28×8/5=13/14-6/7=1/14,亩或等于14分之1,运乎不用简便方法迅悄伍计算比较快。