因式分解x^3-2x+8y^3-4y
问题描述:
因式分解x^3-2x+8y^3-4y
答
x^3-2x+8y^3-4y=(x^3+8y^3)-(2x+4y)=(x+2y)(x²-2xy+4y²)-2(x+2y)=(x+2y)[(x²-2xy+4y²)-2]=(x+2y)(x²-2xy+4y²-2)注:x³+y³=(x+y)(x²-xy+y²)