pur si simplu inlocuieste.
(1+√2)²-(√2+1)(√2-1)+(√2-1)² supra (√2+1)²-(√2-1)²+1=1²+2√2+(√2)²-[(√2)²-1²]+(√2)²-2√2+1²=1+2√2+2-(2-1)+4-2√2+1=
redu 2√2 si -2√2
=1+2-1+4+1=
redu 1 si -1
=7
(√5-2)²-(√5-2)(√5+2)+(√5+2)² supra (√5-2)²-(√5+2)+1=5-4√5+4-5-4+5+4√5+4 supra 5+4√5+4-5+4√5-4-5-4√5-4+1=
Redu
5 si -5
-4√5 si 4√5
