六道因式分解,好的加分!@
1.4x^4-x^2-6x-9
2.16-8x+x^2-9x^4
3.a^4·b-a^2·b^3+a^3·b^2-ab^4
4.x^2-5xy+6y^2-3x+6y
5.a^2-3ab-4b^2-3a+12b
6.a^2+x(x-b)+A(2X-B)
参考答案:.4x^4-x^2-6x-9
=4x^4-(x^2+6x+9)
=(2x^2)^2-(x+3)^2
=(2x^2+x+3)(2x^2-x-3)
=(2x^2+x+3)(2x-3)(x+1)
16-8x+x^2-9x^4
=(16-8x+x^2)-(3x^2)^2
=(x-4)^2-(3x^2)^2
=(3x^2+x-4)(x-4-3x^2)
=(3x+4)(x-1)(x-4-3x^2)
a^4·b-a^2·b^3+a^3·b^2-ab^4
=a^2*b(a^2-b^2)+ab^2(a^2-b^2)
=ab(a^2-b^2)(a+b)
=ab(a-b)(a+b)^2
x^2-5xy+6y^2-3x+6y
=(x-2y)(x-3y)-3(x-2y)
=(x-2y)(x-3y-3)
a^2-3ab-4b^2-3a+12b
=(a-4b)(a+b)-3(a-4b)
=(a-4b)(a+b-3)
a^2+x(x-b)+a(2x-b)
=(a+x)(a+x-b)