Question

31×870+13×310用小学四年级简便计算怎么做

Answer 1

=31*870+13*31*10
=31*870+31*130
=31*(870+130)
=31*1000
=31000

Answer 2

=（31*10*87）+13*310
=31*10*87+13*310
=310*87+13*310
=310*（87+13）
=310*100
31000

Answer 3

=31x870+130x31
=31x（870+130）
=31000

Answer 4

31×870+13×310＝310×87+13×310＝310×（87+13）＝310×100＝31000.望采纳

追答

采纳a

Answer 5

31×870+13×310=31×870+13×31×10=31×870+130×31=31×（130+870）=31×1000=31000