怎么简便计算66×21+19×21+85×19=?_数学解答

怎么简便计算66×21+19×21+85×19=?

人气：100 ℃　时间：2019-10-11 13:20:54

解答

66×21+19×21+85×19 =(66+19)×21+85×19 =85×21+85×19 =85×(21+19) =85×40 =3400 希望能够帮助你!1