3.(1-x)(1+x) paiii pt ca intre cele 2 paranteze este inmultire se face: 3.(1laput2 -xla put 2) (este minus deoarece minus inmultit cu pkus face minus sunt niste reguli ) 3.(1-xla put2)=3-3xla put 2= -3xlaput2= -3/.(-1)=3xlaput2=3/:3=>xlaput2=1=>x = 1
