求①x³+9+3x²+3x.的因式分解.
问题描述：
求①x³+9+3x²+3x.的因式分解.
①x³+9+3x²+3x
②2x²+4xy+2y²-8z²
答
①x³+9+3x²+3x=(x³+3x²+3x+1)+8=(x+1)³+8=(x+1+2)[(x+1)²+4-2(x+1)]=(x+3)(x²+3)②2x²+4xy+2y²-8z²=2[(x²+2xy+y²)-4z²]=2[(x+y)²-4z²]...x^5-x³+x²-1a²+2ab+b²+2ac+2bc+c²xy-1+x-y（x⁴-x+1）²-3（x²-x）-7就只有这几题了- -。求解!!!~x^5-x³+x²-1=x³(x²-1)+(x²-1)=(x²-1)(x³+1)=(x+1)(x-1)(x+1)(x²-x+1)=(x+1)²(x-1)(x²-x+1)a²+2ab+b²+2ac+2bc+c²=(a+b+c)²xy-1+x-y=xy+x-(y+1)=x(y+1)-(y+1)=(y+1)(x-1)