简算:20-(2/15+1/21)×105第二题17/19×(6/17×2-5/49)第三题0.12

问题描述:

简算:20-(2/15+1/21)×105第二题17/19×(6/17×2-5/49)第三题0.12
5×24×7列算式
1个回答 分类:数学 2014-12-14

问题解答:

我来补答
20-(2/15+1/21)×105
=20-(14+5)
=20-19
=1
17/19×(6/17×2-5/49)
=1/19×(12-17*5/49)
=1/19×(12-85/49)
=(588-85)/17*49
=503/17*49
=503/833
0.125×24×7
=0.125×8×3×7
=1×21
=21
 
 
展开全文阅读
剩余:2000