Câu trả lời:
\(\dfrac{x-y}{x^3+y^3}.Q=\dfrac{x^2-2xy+y^2}{x^2-xy+y^2}\)
\(\Leftrightarrow Q=\dfrac{x^2-2xy+y^2}{x^2-xy+y^2}:\dfrac{x-y}{x^3+y^3}\)
\(\Leftrightarrow Q=\dfrac{x^2-2xy+y^2}{x^2-xy+y^2}.\dfrac{x^3+y^3}{x-y}\)
\(\Rightarrow Q=\dfrac{\left(x-y\right)^2.\left(x+y\right)\left(x^2-xy+y^2\right)}{\left(x^2-xy+y^2\right)\left(x-y\right)}\)
\(\Rightarrow Q=\left(x-y\right)\left(x+y\right)\)