已知x.y满足（x-y+2＞＝0.x+y-4＞＝0.2x-y-5＜＝0）,求Z=[x+2y-4]的最大值……补充：[]为

已知x.y满足（x-y+2＞＝0.x+y-4＞＝0.2x-y-5＜＝0）,求Z=[x+2y-4]的最大值……补充：[]为绝对值符号…