Odpowiedzi

2010-03-17T16:42:09+01:00
(5x+4)(5x-4)-(5x-2)2=
=25x²-20x+20x-16 -10x+4 =
=25x²-10x-12

1/4(b+2a)(b-2a)-(1/2b-a)2=
=¼ (b²-4a²) -b+2a=
=¼b²-a²-b+2a