Question

вычислите пожалуйста

Answer 1

$\frac{4}{2+ \sqrt{2} } -5+2 \sqrt{2}= \frac{4-5(2+ \sqrt{2})+2 \sqrt{2} (2+ \sqrt{2})}{2+ \sqrt{2} }= \frac{4-10-5\sqrt{2}+4 \sqrt{2} + 2*2}{2+ \sqrt{2} }= \\ =\frac{4-10+4-5\sqrt{2}+4 \sqrt{2}}{2+ \sqrt{2} }= \frac{-2-\sqrt{2}}{2+ \sqrt{2} }= \frac{-(2+\sqrt{2})}{2+ \sqrt{2} }= -1$