Question

Answer 1

\(\dfrac{x^6}{27}+\dfrac{-x^4y}{3}-x^2y-1y^3\)

\(=\left(\dfrac{x^2}{3}\right)^3+3\cdot\left(\dfrac{x^2}{3}\right)^2\cdot-y+3\cdot\dfrac{x^2}{3}\cdot\left(-y\right)^2+\left(-y\right)^3\)

\(=\left(\dfrac{x^2}{3}+-y\right)^3\)

\(=\left(\dfrac{x^2}{3}-y\right)^3\)

\(=\left(\dfrac{x^3}{3}-\dfrac{3y}{3}\right)^3\)

\(=\left(\dfrac{x^3-3y}{3}\right)^3\)