图
看
解: 145×77+145×21=145×(77+21)=145×98=145×(100-2)=14500-290=14210
145x77+145x21=145x(77+21)=145x98=145x(100-2)=145x100-145x2=14500-290=14210
145×77+145×21=145×(77+21)=145×98=145×(100-2)=14500-290=14210