简便计算: 2.4×99 , 3.19×7.85+1.15×3.19+3.19_数学解答

简便计算: 2.4×99 , 3.19×7.85+1.15×3.19+3.19

人气：118 ℃　时间：2020-06-02 04:50:57

解答

2.4*(100-1)
=2.4*100-2.4*1
=237.6
3.19*7.85+1.15*3.19+3.19
=3.19*7.85+3.19*1.15+3.19*1
=3.19*(7.85+1.15+1)
=31.9