Răspuns:
[tex]a = 6 \sqrt{18} +4 \sqrt{2} - 15 \sqrt{2} + \frac{4 \sqrt{5} }{ \sqrt{10} } - 5 \sqrt{2} \\ a = 18 \sqrt{2} - 11\sqrt{2} + \frac{4}{ \sqrt{2} } - 5 \sqrt{2} \\ a = 7 \sqrt{2} + \frac{4 \sqrt{2} }{2} - 5 \sqrt{2} \\ a = 2 \sqrt{2} + 2 \sqrt{2} \\ a = 4 \sqrt{2} [/tex]
Aici ai rezolvarea.
