神马品牌网工笔画入门 pdf:因式分解
来源：百度文库 编辑：神马品牌网 时间：2024/04/27 16:40:54
设X2-Y2-Z2=0,试将X3-Y3-Z3分解成一次因式之和
X2是X的平方,X3是X的立方
X2是X的平方,X3是X的立方
z^2=x^2-y^2=(x+y)(x-y)
y^2=x^2-z^2=(x+z)(x-z)
x^3-y^3-z^3
=(x-y)(x^2+xy+y^2)-z(x+y)(x-y)
=(x-y)(x^2+xy+y^2-zx-zy)
=(x-y)(x^2-zx+xy-zy+y^2)
=(x-y)((x*(x-z)+y(x-z)+(x+z)(x-z))
=(x-y)(x-z)(2x+y+z)