用乘法分配律
=（1999+1）X99.9
=2000X99.9
=199800

如果您认可我的答案,请点击下面的“选为满意回答”按钮,谢谢!1.748*370-174.8*1.9+17.48*821.748*370-174.8*1.9+17.48*82=1.748X(370+1900+820)=1.748X3090=5401.32答案不对125*456/7.89/4.56*78.9/1.257.48*369369-3.69*748748