x³-y³和x³+y³怎么因式分解
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x³-y³和x³+y³怎么因式分解
x³-y³和x³+y³怎么因式分解
x³-y³和x³+y³怎么因式分解
X³-Y³=X³-XY²+XY²-Y³
=X(X²-Y²)+Y²(X-Y)
=X(X-Y)(X+Y)+Y²(X-Y)
=(X-Y)[X(X+Y)+Y²]
=(X-Y)(X²+XY+Y²)
X³+Y³=X³+X²Y-X²Y+Y³
= X²(X+Y)-Y(X²-Y²)
=X²(X+Y)-Y(X-Y)(X+Y)
=(X+Y)[X²-Y(X-Y)]
=(X+Y)(X²-XY+Y²)
x^3-y^3=(x-y)(x^2+xy+y^2)
x^3+y^3=(x+y)(x^2-xy+y^2)
x³-y³=(x-y)(x²+xy+y²)
x³+y³=(x+y)(x²-xy+y²)
最省脑子的方法:就是这两个都是公式,有理可依的,背下来以后直接用就可以。x³-y³=(x-y)(x²+xy+y²)
x³+y³=(x+y)(x²-xy+y²)