Stabiliti daca rezultatul sumei x+y+z este un numar rational:
a)
[tex] x= \sqrt{2} + \sqrt{3} [/tex]
[tex]y = - 2 \sqrt{3} + 8 \sqrt{2} [/tex]
[tex]z = - 9 \sqrt{2} + \sqrt{3} [/tex]
b)
[tex]x = 2 \sqrt{2} + 3 \sqrt{3} - 5 \sqrt{5} [/tex]
[tex]y = 6 \sqrt{3} - 7 \sqrt{5} - 8 \sqrt{2} [/tex]
[tex]z = 2 \sqrt{5} - 3 \sqrt{3} + 6 \sqrt{2} [/tex]



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