﹙1½+½+⅓+¼﹚÷﹙½+⅓+¼﹚

问题描述:

﹙1½+½+⅓+¼﹚÷﹙½+⅓+¼﹚

=(18/12+6/12+4/12+3/12)÷(6/12+4/12+3/12)
=31/12÷13/12
=31/12x12/13
=31/13