(1) (6800-2000)*0.15-125=595(2)30000*80%*30%=7200>3000,个税(30000*80%-3000)*30%-2000=4300(3)两次合并一次,(3000+2000)*80%*20%*70%=560(4)免税合计(1)+(2)+(3)+(4)=5455