Question

Calculati: $\frac{4}{2+ \sqrt{2} } - 5 + 2 \sqrt{2}$

Answer 1

1×(2-√2) 
_______         -5+2√2=
(2+√2)×(2-√2)

=1×(2-√2)
 ________  -5+2√2=
2²-√2²

1×(2-√2)
________    -5+2√2=
2²-2

1×(2-√2)
_______    -5+2√2=
4-2

1×(2-√2)
________  -5+2√2=
     2

2-√2
_____  -5+2√2
  2