Question

$\frac{4}{2+ \sqrt{2} } -5+2 \sqrt{2}$
Va rog muuult!

Answer 1

$\frac{4}{2+ \sqrt{2} }-5+2 \sqrt{2} (amplificam la fractie cu 2- \sqrt{2} ) =\ \textgreater \ \frac{8-4 \sqrt{2} }{2} -5+2 \sqrt{2}$$=4-4 \sqrt{2 } -5+2 \sqrt{2} =-1-2 \sqrt{2}$