Respuesta :
Step-by-step explanation:
Hope it helps If u have any confusion regarding this kindly inform me , i will try my best to answer

[tex]\tt\displaystyle\ \star a^2-b^2=(a-b)(a+b)\star\\\\ a^2-2(a+b)-b^2=a^2-b^2-2(a+b)=\\\\\underline{(a+b)}(a-b)-2\underline{(a+b)}=\boxed{(a+b)(a-b-2)}[/tex]