Odpowiedź :
[tex]2\sqrt{49} - 6\sqrt{7} + 3\sqrt{7}-\sqrt{28} = 2\cdot7 -3\sqrt{7} -\sqrt{4\cdot7} = 14-3\sqrt{7}-2\sqrt{7} = 14-5\sqrt{7}[/tex]
[tex]2\sqrt{49} - 6\sqrt{7} + 3\sqrt{7}-\sqrt{28} = 2\cdot7 -3\sqrt{7} -\sqrt{4\cdot7} = 14-3\sqrt{7}-2\sqrt{7} = 14-5\sqrt{7}[/tex]