Odpowiedzi

2009-09-27T17:05:14+02:00
A) (x+7)²=x²+14x+49

B) (2x-1)²=4x²-4x+1

C) (4a-2)(4a+2)=16a²-4

D) 3(2a+1)(2a-1)=3(4a²-1)=12a²-3