根据题意a+2=0，a+b+5=0，解得a=-2，b=-33a^2b-[2a^2b-(3ab-a^2-4a^2)]-2ab=3a^2b-2a^2b+(3ab-a^2-4a^2)-2ab=a^2b+ab-5a^2=4*(-3)+(-2)(-3)-5*4=-12+6-20=-26
