大t家好,我是新来接替XX工c作的工d程师,很高兴认1识大g家,希望大a家以7后能多多关照。 Everybody, nice to meet you all, I am the new engineer taking over the work of XX, I really appreciate your assistance in the future。 Thank yo...
解:设多多家收入为X元,支出为Y元,根据题意可得到如下方程组: X-Y=1200 ① X(1+15%)-Y(1-10%)=1200+1380 ② 由①得: X=1200+Y ③ 将③代入②,得: (1200+Y)×(1+15%)-Y(1-10%)=1200+1380 (1200+Y)×1.15-0.9Y=2580 1380+1.15Y-0.9Y=2580 ...