因式分解难题及答案

如题所述

当a=1时,
a^4+b^4+c^4+1+8abc-2(b^2*c^2+c^2*a^2+a^2*b^2+1+b^2+c^2)
=b^4+c^4+2+8bc-2(b^2*c^2+2c^2+2b^2+1)
=b^4+c^4+8bc-2(b^2*c^2+2c^2+2b^2)
=b^4+c^4-2b^2*c^2-4(c^2+b^2-2bc)
=(c^2-b^2)^2 - (2(c-b))^2
=(c^2-b^2+2(c-b))*(c^2-b^2- 2(c-b))
=(c-b))*(c+b+2)*(c-b))*(c+b-2)
=(b-c))*(c+b+2)*(b-c))*(c+b-2)

当a=-1时,
a^4+b^4+c^4+1+8abc-2(b^2*c^2+c^2*a^2+a^2*b^2+1+b^2+c^2)
=b^4+c^4+2-8bc-2(b^2*c^2+2c^2+2b^2+1)
=b^4+c^4-2b^2*c^2-4(c^2+b^2-2bc)
=(c^2-b^2)^2 - (2(c-b))^2
=(c^2-b^2+2(c-b))*(c^2-b^2- 2(c-b))
=(c-b)(c+b+2)(c-b)(c+b-2)
=(b-c))*(c+b+2)*(b-c))*(c+b-2)
结合常数项是1,

结合常数项是1,猜想,因式中有a-1,来对应
a=1时,因式中有a-1+b-c
a=-1时,因式中有a-1+b+c
因式中有a+1,来对应
a=1时,因式中有a+1+b+c
a=-1时,因式中有b-c+a+1
观察,b=1 ,-1 c=1 ,-1
可以得到,
a+b+c+1 a+b-c-1 a-b+c-1 a-b-c+1
来验证原式的分解
温馨提示:答案为网友推荐,仅供参考
第1个回答  2012-01-09
(1)x2-8xy+15y2+2x-4y-3;   (2)x2-xy+2x+y-3;
答案:
x2-8xy+15y2+2x-4y-3;
1 -3
1 -5
=(x-3y)(x-5y)+2x-4y-3
x-3y -1
x-5y 3
x2-8xy+15y2+2x-4y-3=(x-3y-1)(x-5y+3)
(2)x2-xy+2x+y-3
1 2
1 -1
=(x+2y)(x-y)+2x+y-3
x+2y 3
x-y -1
x2-xy+2x+y-3=(x+2y+3)(x-y-1)本回答被提问者采纳
第2个回答  2012-05-20
6x^2 -5xy +y^2 +17x -7y +12
分别当x=0,y=0时得到的结果为:
1. (2x+3)(3x+4)
2. (3-y)(4-y)
第3个回答  2012-05-04
x2-xy+2x+y-3
=x2-1-xy+y+2x-2
=(x+1)(x-1)-y(x-1)+2(x-1)
=(x-1)(x+1-y+2)
=(x-1)(x-y+3)
第4个回答  2012-05-23
谢谢
相似回答