Укажите пары значений \(\displaystyle x\) и \(\displaystyle y{\small,}\) при которых выражение \(\displaystyle \frac{xy}{x-y}\) не имеет смысла.

• \(\displaystyle x=3{\small;} \) \(\displaystyle y=3\)
• \(\displaystyle x=5{\small;} \) \(\displaystyle y=5\)
• \(\displaystyle x=5{\small;} \) \(\displaystyle y=-5\)
• \(\displaystyle x=-3{\small;} \) \(\displaystyle y=3\)