因式分解3x²+4xy-y²
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因式分解3x²+4xy-y²
![因式分解3x²+4xy-y²](/uploads/image/z/19967406-6-6.jpg?t=%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A33x%26sup2%3B%2B4xy-y%26sup2%3B)
不好意思,刚看错了
3x^2+4xy-y^2
=3(x^2+xy*4/3-y^2*1/3)
=3[(x^2+2*2/3*xy+4/9y^2)-y^2/3-4/9y^2]
=3[(x+2/3y)^2-7/9y^2]
=3(x+2/3y+√7/3y)(x+2/3y-√7/3y)
=3[x+(2+√7)/3y][x+(2-√7)/3y]
3x^2+4xy-y^2
=3(x^2+xy*4/3-y^2*1/3)
=3[(x^2+2*2/3*xy+4/9y^2)-y^2/3-4/9y^2]
=3[(x+2/3y)^2-7/9y^2]
=3(x+2/3y+√7/3y)(x+2/3y-√7/3y)
=3[x+(2+√7)/3y][x+(2-√7)/3y]