Задание

Найдите знаки множителей:

\(\displaystyle \times\) [?||-]\(\displaystyle 3\) \(\displaystyle 6\)
[?||-]\(\displaystyle 7\) \(\displaystyle 21\) \(\displaystyle -42\)
[?||-]\(\displaystyle 8\) \(\displaystyle 24\) \(\displaystyle -48\)