$\sqrt {a+\sqrt {b}}=\sqrt {a}+\sqrt {b}$
$2\sqrt {a}+\sqrt {b}=?$
$$\sqrt{a+\sqrt{b}}=\sqrt{a}+\sqrt{b}$$$$\Rightarrow$$$$ a+\sqrt{b}=a+b+2\sqrt{a}\cdot \sqrt{b}$$$$\Rightarrow$$$$ 2\sqrt{a}+\sqrt{b}=1$$
$(\sqrt{a+\sqrt{b}})^2=(\sqrt a+\sqrt b)^2\Rightarrow a+\sqrt b=a+b+2\sqrt{a.b}\Rightarrow \sqrt b=b+2\sqrt{a.b}$
$\Rightarrow \sqrt b=\sqrt b(\sqrt b+2\sqrt a)\rightarrow 1=\sqrt b+2\sqrt a$ olacaktır.