a: x^3+27=(x+3)(x^2-3x+9)
b: x^3-1/8=(x-1/2)(x^2+1/2x+1/4)
c: =(2x+y)(4x^2-2xy+y^2)
d: =(2x-3y)(4x^2+6xy+9y^2)
\(a)\) \(x^3+27=x^3+3^3=\left(x+3\right)\left(x^2-3x+9\right)\)
\(b)\) \(x^3-\dfrac{1}{8}=x^3-\left(\dfrac{1}{2}\right)^3=\left(x-\dfrac{1}{2}\right)\left(x^2+\dfrac{1}{2}x+\dfrac{1}{4}\right)\)
\(c)\) \(8x^3+y^3=2x^3+y^3=\left(2x+y\right)\left(4x^2-2xy+y^2\right)\)
\(d)\) \(8x^3-27y^3=2x^3-3y^3=\left(2x-3y\right)\left(4x^2+6xy+9y^2\right)\)
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\(\rightarrow\) Tính Chất :
\(A^3+B^3=\left(A+B\right)\left(A^2-AB+B^2\right)\)
\(A^3-B^3=\left(A-B\right)\left(A^2-AB+B^2\right)\)
