12.35*1.06-200.8*0.6=12.35*（1+0.06）-(200+0.8)*0.6=12.35+12.35*0.06-200*0.6-0.8*0.6=12.35-200*0.6+12.35*0.06-8*0.06=12.35-120+(12.35-8)*0.06=12.35-120+4.35*0.06=12.35-120+0.261=-107.389啊啊啊啊啊，对不起，打错题目了12.35+5/7-（2.35-2/7）这个才是12.35+5/7-（2.35-2/7）=12.35+5/7-2.35+2/7=12.35-2.35+5/7+2/7=（12.35-2.35）+（5/7+2/7）=10+1=11多谢