(45+17) ×20怎样简便计算
问题描述：
(45+17) ×20怎样简便计算
答
(45+17)×20
=45×20+17×20
=900+340
=1240
(45+17) ×20怎样简便计算
(45+17)×20
=45×20+17×20
=900+340
=1240