已知|a+1|+(b-2)2=0,求2a2-[8ab+12(ab-4a2)]-12ab的值.

已知|a+1|+(b-2)2=0,求2a2-[8ab+12(ab-4a2)]-12ab的值.

原式=2a2-8ab-12ab+2a2-12ab,=4a2-9ab,∵|a+1|+(b-2)2=0,∴a=-1,b=2,把a=-1,b=2代入原式得:原式=4+9×2=22.