已知A=3a²-3ab+b²,B=3a²-2ab,C=a²-ab,试计算A-2B+3C
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![已知A=3a²-3ab+b²,B=3a²-2ab,C=a²-ab,试计算A-2B+3C](/uploads/image/z/1982730-66-0.jpg?t=%E5%B7%B2%E7%9F%A5A%EF%BC%9D3a%26%23178%3B-3ab%2Bb%26%23178%3B%2CB%EF%BC%9D3a%26%23178%3B-2ab%2CC%EF%BC%9Da%26%23178%3B-ab%2C%E8%AF%95%E8%AE%A1%E7%AE%97A-2B%2B3C)
已知A=3a²-3ab+b²,B=3a²-2ab,C=a²-ab,试计算A-2B+3C
已知A=3a²-3ab+b²,B=3a²-2ab,C=a²-ab,试计算A-2B+3C
已知A=3a²-3ab+b²,B=3a²-2ab,C=a²-ab,试计算A-2B+3C
A-2B+3C
=3a²-3ab+b²-2(3a²-2ab)+3(a²-ab)
=3a^2-3ab+b^2-6a^2+4ab+3a^2-3ab
=(3-6+3)a^2+(-3+4-3)ab+b^2
=b^2-2ab
已知A=3a的平方-3ab+b的平方,B=3a的平方-2ab,C=a的平方-ab,试着计算A-2B+.C=a的平方-ab,试着计算A-2B+3C
A-2B+.C=3a^2-3ab+b^2-2(3a^2-2ab)+a^2-ab=3a^2-3ab+b^2-6a^2+4ab+a^2-ab=-2a^2+b^2
A-2B+3C=3a^2-3ab+b^2-2(3a^2-2ab)+3(a^2-ab)=3a^2-3ab+b^2-6a^2+4ab+3a^2-3ab=b^2-2ab