数学题,知道的告诉我答案吧~有急用

来源:百度知道 编辑:UC知道 时间:2024/06/12 18:23:26
(x-1)(x-3)(x+2)(x+4)+24
(x+y+z)(yz+zx+xy)-xyz
2x平方-3xy-2y平方-2x-11y-12
2x平方+xy-y平方+3x+1
3a平方-5ab+2b平方-a-b-10
按b的降幕排列,3a平方-5ab+2b平方-a-b-10
按a的降幕排列,a平方+2ab+b平方-x平方-6x-9
谢谢~啦

(x-1)(x-3)(x+2)(x+4)+24
=48 - 14 x - 13 x^2 + 2 x^3 + x^4
=(-2 + x) (3 + x) (-8 + x + x^2)

(x+y+z)(yz+zx+xy)-xyz
=x^2 y + x y^2 + x^2 z + 2 x y z + y^2 z + x z^2 + y z^2
=(x + y) (x + z) (y + z)

2x^2-3x y-2y^2-2x-11y-12
=(-3 + x - 2 y) (4 + 2 x + y)

2x^2+x y-y^2+3x+1
=(1 + 2 x - y) (1 + x + y)

3a^2-5a b+2b^2-a-b-10
=(5 + 3 a - 2 b) (-2 + a - b)

a^2+2a b+b^2-x^2-6x-9
=(-3 + a + b - x) (3 + a + b + x)