Раскройте скобки:

\(\displaystyle -7 \cdot (-a-b\,)=\)[?||-][ ][?|+|-][ ]

\(\displaystyle -(-x-y\,)=\)[?||-][ ][?|+|-][ ]

\(\displaystyle -a\cdot (-b-c\,)=\)[?||-][ ] [?|+|-][ ]