解雹扒消此盯:1)源知 -a^2b+ab-5+(3a^b+4ab+1) = -a^2b+ab-5+3a^b+4ab+1 = 2a^b+5ab-42) 2a^2b+5ab-4 -(-3a^2b+4ab-1) =2a^2b+5ab-4+3a^2b-4ab+1 =5a^2b+ab-3