[tex]\displaystyle\\
\sqrt{x^2 - 4x + 5} =1~~~~~\Big| ~\text{ (Ridicam la puterea a 2-a)} \\\\
x^2 - 4x + 5 = 1^2\\\\
x^2 - 4x + 5 = 1\\\
x^2 - 4x + 5-1 = 0\\\
x^2 - 4x + 4 = 0\\\
(x-2)^2 = 0\\\\
\bf Solutia:~~~\boxed{\bf x_1 + x_2 = 2}\\\\
Verificare~ in~ ecuatia~ initiala:\\\\
\sqrt{x^2 - 4x + 5}=\sqrt{2^2 - 4\cdot 2 + 5} = \sqrt{4 - 8 + 5} =\sqrt{1} =1~~OK
[/tex]
