Odpowiedzi

2009-09-23T15:02:53+02:00
(4a+2)²-(a-2)² =16a²+16a+4-a²+4a-4=15a²+20a

(2x+y)(x-2y)-3(x-y)²=2x²-4xy+xy-2y²-3(x²-2xy+y²)=
2x²-4xy+xy-2y²-3x²+6xy-3y²=-x²+3xy-5y²
2009-09-23T15:10:11+02:00
(4a+2)²-(a-2)² =4a²+16-a²+4=3a²+20
(2x+y)(x-2y)-3(x-y)²= 2x²-4xy+yx-2y²-3x²+3y²=
= -x²-3xy+y²
2009-09-23T16:16:16+02:00
(4a+2)²-(a-2)² = 8a²+4-a²+4=9a²+8

(2x+y)(x-2y)-3(x-y)²=2x²-2y²-3x²+3y²=-x²+y²