C=-(a^2+10ab-24b^2)=-(a-2b)(a+12b)
A=3a^2+4ab-察槐坦1/2b^2吗 解:败桐明握2A-B+C=0C=B-2A=(5a^2-2ab)-2(3a^2+4ab-1/2*b^2) =5a^2-2ab-6a^2-8ab+b^2 =-a^2-10ab+b^2