用拆项法分解因式x的3次方减去3倍x的平方加上4
问题描述：
用拆项法分解因式x的3次方减去3倍x的平方加上4
答
x^3-3x^2+4
=x^3-2x^2-x^2+4
=(x^3-2x^2)-(x^2-4)
=x^2(x-2)-(x-2)(x+2)
=(x-2)[x^2-(x+2)]
=(x-2)(x^2-x-2)
=(x-2)(x-2)(x+1)
=(x-2)^2(x+1)
答
x³-3x²+4
=(x³+x²)-(4x²-4)
=x²(x+1)-4(x+1)(x-1)
=(x+1)(x²-4x+4)
=(x+1)(x-2)²
答
x³-3x²+4
把-3x²拆成x²-4x²
=(x³+x²)-(4x²-4)
=x²(x+1)-4(x+1)(x-1)
=(x+1)(x²-4x+4)
=(x+1)(x-2)²