25×4×9÷45,先25×4=100,再100×9=900,900÷45=20
25拆成5*5,45拆成5*9,就是20。。。。。。望采纳
=25÷9÷9÷5×4=5×4=20
25×9÷45x4=5X5X9÷45X4=5x4X45÷45=20X(45÷45)=2Ox1=20
25x9÷45x4=4x5x5x9÷5÷9=20