来自宁国勤的问题
{15/29-(0.25+1/3)*7.2}/14/5
{15/29-(0.25+1/3)*7.2}/14/5
1回答
2020-04-19 08:25
{15/29-(0.25+1/3)*7.2}/14/5
{15/29-(0.25+1/3)*7.2}/14/5
{29/15-(0.25+1/3)*7.2}/14/5
=[29/15-(1/4+1/3)*36/5]*5/14
=(29/15-7/12*36/5)*5/14
=(29/15-21/5)*5/14
=29/15*5/14-21/5*5/14
=29/42-3/2
=-34/42
=-17/21