100*7.9+184*2.1+84*2.9怎么简便计算
问题描述：
100*7.9+184*2.1+84*2.9怎么简便计算
答
100x7.9+184x2.1+84x2.9
=100x7.9+(100+84)x2.1+84x2.9
=100x7.9+100x2.1+84x2.1+84x2.9
=100x(7.9+2.1)+84x(2.1+2.9)
=100x10+84x5
=1420
答
100*7.9+184*2.1+84*2.9
=100*7.9+100*2.1+84*2.1+84*2.9
=100*(7.9+2.1)+84*(2.1+2.9)
=100*10+84*50
=1000+420
=1420