Задание
Расставьте знаки в произведениях:
| \(\displaystyle \times\) | \(\displaystyle -a\) | \(\displaystyle b\) |
| \(\displaystyle -c\) | [?||-]\(\displaystyle a\cdot c\) | [?||-]\(\displaystyle b\cdot c\) |
| \(\displaystyle d\) | [?||-]\(\displaystyle a\cdot d\) | [?||-]\(\displaystyle b\cdot d\) |