﹣240×﹙3又1/2－2又2/3＋10又7/12－4又5/6﹚

﹣240×﹙3又1/2－2又2/3＋10又7/12－4又5/6﹚
﹣240×﹙3又1/2－2又2/3＋10又7/12－4又5/6﹚

﹣240×﹙3又1/2－2又2/3＋10又7/12－4又5/6﹚
﹣240×﹙3又1/2－2又2/3＋10又7/12－4又5/6﹚
=﹣240×﹙3-2+10-4+1/2－2/3＋7/12－5/6﹚
=-240x7-240x1/2+240x2/3-240x7/12+240x5/6
=-1680-120+160-140+200
=-1580

﹣240×﹙3又1/2－2又2/3＋10又7/12－4又5/6﹚
=-240×(7/2-8/3+127/12-29/6)
=-240×7/2-240×(-8/3)-240×127/12-240×(-29/6)
=-840+640-2540+1160
=-1580