Question 71
Find all real numbers $x$ and $y$ for which
$$
x^{3}-y^{3}=7(x-y) \quad \text{and} \quad x^{3}+y^{3}=5(x+y)
$$
$$
x^{3}-y^{3}=7(x-y) \quad \text{and} \quad x^{3}+y^{3}=5(x+y)
$$
MathNet 2005 — Part 03 Question 71
Math Olympiad Vault · MathNet 2005 — Part 03