99.9×98+(1-4/5)×999简便计算_数学解答

99.9×98+(1-4/5)×999
简便计算

人气：184 ℃　时间：2020-04-14 19:15:39

解答

解
99.9×98+(1-4/5)×999
=99.9×98+0.2×999
=99.9×98+2×99.9
=99.9×(98+2)
=99.9×100
=9990