Укажите пары значений \(\displaystyle p\) и \(\displaystyle y{\small,}\) при которых выражение \(\displaystyle \frac{p+y}{py}\) не имеет смысла.

• \(\displaystyle p=0{\small;} \) \(\displaystyle y=7\)
• \(\displaystyle p=20{\small;} \) \(\displaystyle y=0\)
• \(\displaystyle p=-8{\small;} \) \(\displaystyle y=8\)
• \(\displaystyle p=0{\small;} \) \(\displaystyle y=0\)