“微信扫一扫”进入题库练习及模拟考试
参考答案:解:\(( - \frac{3}{7}) + ( + \frac{3}{5}) + ( + \frac{2}{7}) + ( - 1\frac{3}{5})\)
\( = [( - \frac{3}{7}) + ( + \frac{2}{7})] + [( + \frac{3}{5}) + ( - 1\frac{3}{5})]\)
\( = ( - \frac{1}{7}) + ( - 1)\)
\( = - 1\frac{1}{7}\).
解析: