41又1/3×3/4＋51又1/4×4/5
＝﹙40＋4/3﹚×3/4＋﹙50＋5/4﹚×4/5
＝30＋1＋40＋1
v72.在详细点原式＝﹙40＋4/3﹚×3/4＋﹙50＋5/4﹚×4/5 ＝40×3/4＋4/3×3/4＋50×4/5＋5/4×4/5 ＝30＋1＋40＋1 ＝72.