\(8m^3+36m^2n+54mn^2+27n^3\)
\(=\left(2m\right)^3+3\left(2m\right)^2.3n+3.2m\left(3n\right)^2+\left(3n\right)^2\)
\(=\left(2m+3n\right)^3\)
\(a^4-b^4\)
\(=\left(a^2+b^2\right)\left(a-b\right)\left(a+b\right)\)
\(x^3-3x^2+3x-1\)
\(=\left(x^3-1\right)-3x\left(x-1\right)\)
\(=\left(x-1\right)\left(x^2+x+1\right)-3x\left(x-1\right)\)
\(=\left(x-1\right)\left(x^2-2x+1\right)\)
\(=\left(x-1\right)^3\)
\(x^3+9x^2y+27xy^2+27y^3\)
\(=x^2+3x^2.3y+3x\left(3y\right)^2+\left(3y\right)^3\)
\(=\left(x+3y\right)^3\)
