26.39*36+26.39*83-263.9*1.9簡算

26.39*36+26.39*83-263.9*1.9簡算

原式=26.39*36+26.39*83-26.39*10*1.9
=26.39*36+26.39*83-26.39*190
然後把26.39提出來
=26.39*(36+83+190)
=26.39*309
=8154.51