分解因式分解因式
3x^2-11xy+6y^2-xz-4yz-2z^2
(1)x^2+px+q=(x-x1)(x-x2)
x1+x2=-p x1x2=q
(2)ax^2+bx+c=a(x^2+bx/a +c/a)=a(x-x1)(x-x2)
x1+x2=-b/a x1x2=c/a
(3)ax^2+bx+c=(mx-p)(nx-q)
mn=a pq=c -pn-qm=b
(4)3x^2-11xy+6y^2-xz-4yz-2z^2
=3x^2-(11y+z)x+6y^2-4yz-2z^2 *
=3x^2-(11y+z)x+(6y+2z)(y-z)
=3x^2-(11y+z)x+2(3y+z)(y-z) **
=(3x-2y+2...全部
(1)x^2+px+q=(x-x1)(x-x2)
x1+x2=-p x1x2=q
(2)ax^2+bx+c=a(x^2+bx/a +c/a)=a(x-x1)(x-x2)
x1+x2=-b/a x1x2=c/a
(3)ax^2+bx+c=(mx-p)(nx-q)
mn=a pq=c -pn-qm=b
(4)3x^2-11xy+6y^2-xz-4yz-2z^2
=3x^2-(11y+z)x+6y^2-4yz-2z^2 *
=3x^2-(11y+z)x+(6y+2z)(y-z)
=3x^2-(11y+z)x+2(3y+z)(y-z) **
=(3x-2y+2z)(x-3y-z)
*6=6×1 , -2=2×(-1)
**3=3×1 ,2（3y+z)(y-z）=-2(y-z)×(-1)(3y+z)
。
收起
