已知A=3a2+b2-c2,B=-2a2-b2+3c2,且A+B+C=0,则C=_.

问题描述:

已知A=3a2+b2-c2,B=-2a2-b2+3c2,且A+B+C=0,则C=______.

∵A+B+C=0,
∴C=-A-B=-(3a2+b2-c2)-(-2a2-b2+3c2
=-3a2-b2+c2+2a2+b2-3c2
=-a2-2c2
故答案为:-a2-2c2