Раскройте скобки:
\(\displaystyle -3 \cdot (x-y\,)=\)[?||-][ ][?|+|-][ ]
\(\displaystyle -(a-b\,)=\)[?||-][ ][?|+|-][ ]
\(\displaystyle -a\cdot (u-w\,)=\)[?||-][ ] [?|+|-][ ]