题目应该是(5/6+2/3-3/4)ⅹ24吧，(5/6+2/3-3/4)ⅹ24＝5/6*24+2/3*24-3/4ⅹ24＝20+16-18＝18
(5/6+2/3-3/4)×24＝5/6×24+2/3×24-3/4×24 (乘法分配律)＝20+16-18＝18
原式=5/6x24+2/3x24-3/4x24=20+16-18=18
