x²-2x+1=0 metoda I:stim ca (a+b)²=a²+2ab+b² deci x²-2x+1=(x-1)² ⇒x-1=0⇒x=1 metoda II:Δ=(-2)²-1*4=0 deci x1=x2=-b/2a=2/2=1

x^2 - 2x + 1 = 0  d = 4 - 4 = 0  Daca delta = 0 => ecuatia are solutii reale x1=x2= - b/2a = 2/2 = 1