|2M+1|+(N+2)^4=0
∵|2M+1|≥0,(N+2)^4≥0
∴2M+1=N+2=0
∴M=-½,N=-2
∴MN=1不是等于负40么题目给的不清楚啊|2M+1|+N+2=01° M＜-1/2-2M-1+N+2=0-2M+N=-12° M=-1/2N=-2MN=13° M＞-1/22M+N=-3这怎么算嘛