2又2/3÷(9/2)+2又兄敬2/3×7/9的简便方旦瞎法2又2/3÷(9/羡迟慎2)+2又2/3×7/9=2又2/3×2/9+2又2/3×7/9=2又2/3×（2/9+7/9）=2又2/3×1=2又2/3
