19.98*37-1998.8*1.9+19998等于多少(过程)
问题描述：
19.98*37-1998.8*1.9+19998等于多少(过程)
答
19.98*37-1998.8*1.9+19998
=1998*0.37-(1998+0.8)*1.9+19998
=1998*0.37-1998*1.9-0.8*1.9+19998
=1998*(0.37-1.9)-0.8*1.9+19998
=-1998*1.53-0.8*1.9+19998
=16939.54