Odpowiedzi

2009-10-11T13:07:11+02:00
Cos brak chyba albo chodzi o to:

(X+y)²=x²+2x+1
(x-y-1)²=(x-y-1)(x-y-1)=x²-xy-x-yx+y²+y-x+y+1=x²+y²-2xy-2x+2y+1
x³+y³=(x+y)(x²-xy+y²)
  • Użytkownik Zadane
2009-10-11T13:08:42+02:00

(x+y)²=x²+2xy+y²
lub (x+y)²=(x+y)(x+y)=x*x+x*y+y*x+y*y=x²+2xy+y²

(x-y-1)²=(x-y-1)(x-y-1)=x*x-x*y-x*1-y*x+y*y+y*1-1*x+1*y+1*1=
x²-xy-x-yx+y²+y-x+y+1=x²-2xy+y²-2x+2y+1
lub (x-y-1)²=(x-(y+1))²=x²-2*x*(y+1)+(y+1)²=x²-2xy-2x+y²+2y+1

x³+y³=(x+y)(x²-xy+y²)
2009-10-11T14:26:43+02:00