x^3-x^2y-4y^3 怎么因式分解啊?
问题描述:
x^3-x^2y-4y^3 怎么因式分解啊?
答
x³-x²y-4y³ (加一个4y³,减一个4y³)=x³-4y²-4y³-x²y+4y³=(x³-8y³)-(x²y-4y³)=(x-2y)(x²+2xy+4y²)-y(x²-4y²)=(x-2y)(x...
x^3-x^2y-4y^3 怎么因式分解啊?
x³-x²y-4y³ (加一个4y³,减一个4y³)=x³-4y²-4y³-x²y+4y³=(x³-8y³)-(x²y-4y³)=(x-2y)(x²+2xy+4y²)-y(x²-4y²)=(x-2y)(x...