（1）原式=1580*2.9-910*2.9+330*7.9
=（1580-910）*2.9+330*7.9
=330*2.9+330*7.9
=330*（2.9+7.9）
=3564
(2) 原式=2009/37+300/37/3
=2009/37+100/37
=（2009+100）/37
=57
呵呵,以后要会做哦收到呵呵，第一道错了原式=1580*2.9-910*2.9+330*7.9 =（1580-910）*2.9+330*7.9 =670*2.9+330*7.9 =330*2*2.9+10*2.9+330*7.9 =（5.8+7.9）*330+29 =4550