Задание

Расставьте знаки в произведениях:

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