Tìm Q biết ​\(\begin{array}{l} \frac{{x - y}}{{{x^3} + {y^3}}} \cdot Q = \frac{{{x^2} - 2xy + {y^2}}}{{{x^2} - xy + {y^2}}} \end{array}\)

* Hướng dẫn giải

 \(\begin{array}{l} \frac{{x - y}}{{{x^3} + {y^3}}} \cdot Q = \frac{{{x^2} - 2xy + {y^2}}}{{{x^2} - xy + {y^2}}}\\ \Rightarrow Q = \frac{{{x^2} - 2xy + {y^2}}}{{{x^2} - xy + {y^2}}}:\frac{{x - y}}{{{x^3} + {y^3}}}\\ = \frac{{{{(x - y)}^2}}}{{{x^2} - xy + {y^2}}} \cdot \frac{{(x + y)\left( {{x^2} - xy + {y^2}} \right)}}{{x - y}}\\ = (x - y)(x + y) = {x^2} - {y^2} \end{array}\)