- 63 名前：１３２人目の素数さん mailto:sage [2013/03/23(土) 02:55:23.60 ]
- 暇だから全部書いちゃおうかな、、
2(1) x^2y-2xyz-y-xy^2+x-2z
=-2z(xy+1)+xy(x-y)+x-y
=-2z(xy+1)+(xy+1)(x-y)
=(xy+1)(x-y-2z)
(別解1)
x^2y-2xyz-y-xy^2+x-2z
=x^2y+(-2yz-y^2+1)x-2z-y
=(yx+1)(x-2z-y)
(別解2)
x^2y-2xyz-y-xy^2+x-2z
=-xy^2+(x^2-2xz-1)y+x-2z
=(xy+1)(-y+x-2z)
(2)6x^2-xy-2y^2-7x+7y-3
=6x^2+(-y-7)x-2y^2+7y-3
=6x^2+(-y-7)x-(2y-1)(y-3)
=(2x+y-3)(3x-2y+1)
(別解)
6x^2-xy-2y^2-7x+7y-3
=-2y^2+(7-x)y+6x^2-7x-3
=-2y^2+(7-x)y+(3x+1)(2x-3)
=(-2y+3x+1)(y+2x-3)
