Răspuns :
[tex]-\sqrt 5 - \sqrt 5 = -(\sqrt 5+ \sqrt 5) = -(2\sqrt5) = \\= -2\sqrt5[/tex]
[tex]-\sqrt 5 - \sqrt 5 = \sqrt 5\cdot (-1-1) = \sqrt 5 \cdot (-2) = \\ -\sqrt 5 \cdot 2 = -2\sqrt 5[/tex]
[tex]-\sqrt 5 - \sqrt 5 = \sqrt 5\cdot (-1-1) = \sqrt 5 \cdot (-2) = \\ -\sqrt 5 \cdot 2 = -2\sqrt 5[/tex]