Задание

Расставьте знаки в произведениях:

\(\displaystyle \times\) \(\displaystyle a\) \(\displaystyle -b\)
\(\displaystyle -c\) [?||-]\(\displaystyle a\cdot c\) [?||-]\(\displaystyle b\cdot c\)
\(\displaystyle d\) [?||-]\(\displaystyle a\cdot d\) [?||-]\(\displaystyle b\cdot d\)