可以用简便计算: 5/6-(1/5+1/3)÷8/9 =5/6-(1/5×9/8+1/3×9/8) =5/6-3/5 =7/30得出等于7/30
解:5/6-[(1/5+1/3)÷8/9]=5/6-[(3/15+5/15)÷8/9]=5/6-[8/15÷8/9]=5/6-8/15×9/8=5/6-3/5=25/30-18/30=7/30
5/6-【(1/5+1/3)÷8/9】=5/6-(8/15÷8/9)=5/6-3/5=7/30