Dane są wyrażenia
[tex]\text{P}=-4a^2b+ab-b^3\\\\\text{Q}=4a^2b-2ab+b^3[/tex]
Suma P + Q
[tex]\text{P}+\text{Q}=-4a^2b+ab-b^3+(4a^2b-2ab+b^3)=\\\\=-4a^2b+ab-b^3+4a^2b-2ab+b^3=\\\\=-4a^2b+4a^2b+ab-2ab-b^3+b^3=\boxed{-ab}[/tex]
Różnica P - Q
[tex]\text{P}-\text{Q}=-4a^2b+ab-b^3-(4a^2b-2ab+b^3)\\\\=-4a^2b+ab-b^3-4a^2b+2ab-b^3=\\\\=-4a^2b-4a^2b+ab+2ab-b^3-b^3=\boxed{-8a^2b+3ab-2b^3}[/tex]
