图
37*49-1703
=37*(50-1)-1703
=37*50-37*1-1703
=1850-37-1703..........................这里可以合并后面的减法=1850-(37+1703)
=1813-1703............................................................................=1850-1740
=110 ........................................................................................=110
37×49-1703
=1813-1703
=110
37×49-1703
=37×(50-1)-1703
=37×50-37×1-1703
=1850-(37+1703)
=1850-1740
=110