Question

Daca
[tex]
p=( \sqrt{5} + \sqrt{2}) ^{2} - \sqrt{2} ( \sqrt{5}+ \sqrt{2})- \sqrt{5} ( \sqrt{2} -2 \sqrt{5}),
[/tex]
atunci aratati ca p∈ N

Answer 1

p=5+2+2√10-√10-2-√10+10=
=7+10-2=15

Answer 2

$(5+2 \sqrt{10} +2 ) - (\sqrt{10} + 2) - (\sqrt{10} - 10)$
 $\\ 7 + 2 \sqrt{10} - \sqrt{10} - 2 - \sqrt{10} + 10$ 
 $\\ 15$