x2-2xy-8y2因式分解
x2-2xy-8y2
=(x-4y)(x+2y)
x2+2xy-8y2+2xy+14yz-3z2二次三次項的因式分解
2xy改為2xz吧!x^2+2xy-8y^2+2xz+14yz-3z^2 =(x+4y-z)(x-2y+3z)方法一:觀察係數1x 4y -1z 1x -2y 3z方法二:待定係數法設為(ax+by+cz)(dx+ey+fz)=x^2+2xy-8y^2+2xz+14yz-3z^2左邊乘開比較係數…
因式分解:x5-3x4+2x3-x2+3x-2
x5-3x4+2x3-x2+3x-2
=x^3(x^2-3x+2)-(x^2-3x+2)
=(x^3-1)(x^2-3x+2)
=(x-1)(x^2+x+1)(x-1)(x-2)
=(x-1)^2(x-2)(x^2+x+1)