简便计算!1.2.5×9.8 2.1.25×25×3.23.2.4-1.375+5分之3 4.3分之1÷7分之3×14分之5_数学解答

简便计算!1.2.5×9.8 2.1.25×25×3.2
3.2.4-1.375+5分之3 4.3分之1÷7分之3×14分之5

人气：382 ℃　时间：2020-02-04 09:52:35

解答

1.2.5×9.8
=2.5x(10-0.2)
=2.5x10-2.5x0.2
=25-0.5
=24.5
2.1.25×25×3.2
=(1.25x8)x(0.4x25)
=10x10
=100
3.2.4-1.375+5分之3
=2.4-+0.6-1.375
=3-1.375
=1.625
4 3分之1÷7分之3×14分之5
=1/3x7/3x5/14
=5/18