t³/8+(1+t/2)³=
=(t/2)³+(1+t/2)³= formula este a³+b³=(a+b)(a²-ab+b²)
=(t/2+1+t/2)[(t/2)²-(t/2)(1+t/2)+(1+t/2)²]=
=(t+1)(t²/4-t/2-t²/4+1+2t/2+t²/4)=
=(t+1)(t²/4+t/2+1)
1-(z+1)⁶=[1-
(z+1)³][1+
(z+1)³]= prima formula folosita a²-b²=(a-b)(a+b)
={(1-z-1)[(1+z+1+(z+1)²]}{(1+z+1)[(1-z-1+(z+1)²]}=
=[(-z)(2+z+z²+2z+1)][(2+z)(-z+z²+2z+1)]=
=(-z)(z²+3z+3)(2+z)(z²+z+1)
