几道初中因式分解
问题描述：
几道初中因式分解
6x^2+7x+2=
4m^2-12m+9=
5+7x-6x^2=
12x^2+xy-6y^2=
2x^2-xy-15y^2=
x^2+x-(a^2-a)=
20a^4-33a^2b^2+7b^4=
(x^2-5x)+10(x^2-5x)-96=
ab(c^2-d^2)+cd(a^2-b^2)=
x^2-4mx+8mn-4n^2=
x^4+64=
x^3-11x^2+31x-21=
x^3-4xy^2-2x^2y+8y^3=
答
6x^2+7x+2=(3x+2)(2x+1)
4m^2-12m+9=(2m-3)^2
5+7x-6x^2=(5-3x)(1+2x)
12x^2+xy-6y^2=(3x-2y)(4x+3y)
2x^2-xy-15y^2=(2x+5y)(x-3y)
x^2+x-(a^2-a)=(x+a)(x-a+1)
20a^4-33a^2b^2+7b^4=(4a^2-b^2)(5a^2-7b^2)
(x^2-5x)+10(x^2-5x)-96=!有错的吧?是不是(x^2-5x)^2+10(x^2-5x)-96=(x²-5x+16)(x-6)(x+1)
ab(c^2-d^2)+cd(a^2-b^2)=(ac-bd)(bc+ad)
x^2-4mx+8mn-4n^2=(x-2n)(x+2n-4m)
x^4+64=(x²+8-4x)(x²+8+4x)
x^3-11x^2+31x-21=(x-1)(x-3)(x-7)
x^3-4xy^2-2x^2y+8y^3=(x-2y)(x^2-4y^2)