已知a=3a²+b²-c²,b=-2a²-b²+3c²,并且a+b+c=o,则c=—-
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![已知a=3a²+b²-c²,b=-2a²-b²+3c²,并且a+b+c=o,则c=—-](/uploads/image/z/1835501-5-1.jpg?t=%E5%B7%B2%E7%9F%A5a%3D3a%26%23178%3B%EF%BC%8Bb%26%23178%3B-c%26%23178%3B%2Cb%3D-2a%26%23178%3B-b%26%23178%3B%EF%BC%8B3c%26%23178%3B%2C%E5%B9%B6%E4%B8%94a%2Bb%2Bc%3Do%2C%E5%88%99c%3D%E2%80%94-)
已知a=3a²+b²-c²,b=-2a²-b²+3c²,并且a+b+c=o,则c=—-
已知a=3a²+b²-c²,b=-2a²-b²+3c²,并且a+b+c=o,则c=—-
已知a=3a²+b²-c²,b=-2a²-b²+3c²,并且a+b+c=o,则c=—-
已知a=3a²+b²-c²,b=-2a²-b²+3c²,并且a+b+c=o,
则c=-a-b=-3a²-b²+c²+2a²+b²-3c²
=-a²-2c²;
解
A+B+C=0
C=-A-B
=-(3a²+b²-c²)-(-2a²-b²+3c²)
=(-3a²+2a²)+(-b²+b²)+(c²-3c²)
=-a²-2c²