根据题意得a+2=0b+1=0∴a=-2b=-15ab²—{2a²b—【3a²b—(4ab²—2a²b）】}=5ab²—2a²b+3a²b—4ab²+2a²b=ab²+3a²b当a=-2,b=-1时原式=-2-12=-14...