а+b(a+b+2)-(a-b)(a-b-2)=a+ab+b2+2b-(a2-ab-2a-ab+b2+2b)=a+ab+b2+2b-a2+ab+2a+ab-b2-2b= =3a-a2+3ab
a+b(a+b+2)-(a-b)(a-b-2)=3a+3ba-a^2=a(3b−a+3)
а+b(a+b+2)-(a-b)(a-b-2)=a+ab+b2+2b-(a2-ab-2a-ab+b2+2b)=a+ab+b2+2b-a2+ab+2a+ab-b2-2b= =3a-a2+3ab
a+b(a+b+2)-(a-b)(a-b-2)=3a+3ba-a^2=a(3b−a+3)