解:(1)原式=4x2﹣2x﹣1﹣{5x2﹣[8x﹣2﹣3x2﹣3x]﹣x2}=4x2﹣2x﹣1﹣{5x2﹣8x+2+3x2+3x﹣x2}=4x2﹣2x﹣1﹣5x2+8x﹣2﹣3x2﹣3x+x2=﹣3x2+3x﹣3 (2)原式=5abc﹣{2a2b﹣[3abc﹣4ab2+a2b]}+3ab2=5abc﹣{2a2b﹣3abc+4ab2﹣a2b}+3ab2=5abc﹣2a2b+3abc﹣4ab2+a2b+3ab2=8abc﹣a2b﹣ab2; 将a,b,c的值代入得:原式=![](http://img.shitiku.com.cn/uploads/allimg/20190817/20190817185142-96640.png) (3)根据题意得,(x﹣2)2+|xy﹣4|=0则,(x﹣2)2=0,|xy﹣4|=0解得:x=2,y=2 原式=3x2y+{﹣2x2y﹣[﹣2xy+(x2y﹣4x2)﹣xy]+xy2}=3x2y+{﹣2x2y﹣[﹣2xy+x2y﹣4x2﹣xy]+xy2}=3x2y+{﹣2x2y+2xy﹣x2y+4x2+xy+xy2}=3x2y﹣2x2y+2xy﹣x2y+4x2+xy+xy2=4x2+3xy+xy2 将x=2,y=2代入得:原式=36 |