分数计算21/25-2/9+4/25-5/9
解题思路:四则运算规则(按顺序计算、先算乘除后算加减,有括号先算括号,有乘方先算乘方)即脱式运算(递等式计算)需在该原则前提下进行
解题过程:
21/25-2/9+4/25-5/9
=21/25+4/25-(5/9+2/9)
=1-7/9
=2/9
存疑请追问,满意请采纳
21/25-2/9+4/25-5/9
=21/25+4/25-2/9-5/9
=25/25-7/9
=1-7/9
=2/9,
所以可以通过计算得到答案是2/9。
依据题意列式计算如下:
21/25-2/9+4/25-5/9
=(21/25+4/25)-(2/9+5/9)
=1-79
=2/9
计算过程如下
原式=21/25+4/25-(2/9+5/9)
=1-7/9
=2/9
21/25-2/9+4/25-5/9
=21/25+4/25-(2/9+5/9)
=1-7/9
=2/9