问题描述: (+2/7)+(-5/2)+(-12/7)+(+2.5)+(-0.125)+(-19/8) 简便计算 1个回答 分类:综合 2014-11-05 问题解答: 我来补答 (+2/7) + (-5/2) + (-12/7) + (+2.5) + (-0.125) + (-19/8)= 2/7 - 2.5 - 12/7 + 2.5 - 1/8 - 19/8= -10/7 -20/8= -( 10/7 + 5/2 )= -( 20/14 + 35/14 )= -55/14 展开全文阅读