38×47-7×38=38*(47-7)=38*40=1520
解:原式=38×(47-7) =38×40 =1520望采纳,谢谢
=38(47-7)=38*40=(40+2)40=1600-80=1520
38X47-7X38=38X(47-7)=38X40=1520