分解因式1,分解因式X²+4Y²+9Z²+4XY-6XYZ-12YZ
2,分解因式2X²+7XY+3Y²+9X+2Y-5
1。原式=x^2+4y^2+9z^2+4xy-6zx-12yz ???
=(x^2+4xy+4y^2)-(6zx+12yz)+9z^2
=(x+2y)^2-6z(x+2y)+(3z)^2
=(x+2y-3z)^2
2。 原式=2x^2+7xy+3y^2+9x+2y-5
=2x^2+(7y+9)x+(3y^2+2y-5)
=2x^2+(7y+9)x+(3y+5)(y-1)
=2x^2+[2(3y+5)+(y-1)]x+(3y-5)(y-1)
=2x^2+2x(3y+5)+(y-1)x+(3y+5)(y-1)
=2x[x+(3y+5)]+(y-1)[x+(3y+5)]
=(x+3y+5)(2...全部
1。原式=x^2+4y^2+9z^2+4xy-6zx-12yz ???
=(x^2+4xy+4y^2)-(6zx+12yz)+9z^2
=(x+2y)^2-6z(x+2y)+(3z)^2
=(x+2y-3z)^2
2。
原式=2x^2+7xy+3y^2+9x+2y-5
=2x^2+(7y+9)x+(3y^2+2y-5)
=2x^2+(7y+9)x+(3y+5)(y-1)
=2x^2+[2(3y+5)+(y-1)]x+(3y-5)(y-1)
=2x^2+2x(3y+5)+(y-1)x+(3y+5)(y-1)
=2x[x+(3y+5)]+(y-1)[x+(3y+5)]
=(x+3y+5)(2x+y-1)。
收起
