Odpowiedzi

2009-12-21T23:07:42+01:00
(2a+b)(2a-b)-(5a+b)²-6(a²-2b²)=
=4a²-b²-(25a²+10ab+b²)-6a²+12b²=
=4a²-b²-25a²-10ab-b²-6a²+12b²=
=-27a²-10ab+10b²