rút gọn :
a, \(\sqrt{x+4\sqrt{ }X-4}+\sqrt{x-4\sqrt{ }x-4}vớix>=8\)
b,\(\sqrt{2x-1+2\sqrt{ }x^2-x}+\sqrt{2x-1-2}\sqrt{x^2}-x\)
c, \(\dfrac{\sqrt{x-2\sqrt{x+1}}}{x+2\sqrt{ }x+1}\left(x>=0\right)\)
d, \(\dfrac{x-1}{\sqrt{ }y-1}\cdot\sqrt{\dfrac{\left(y-2\sqrt{y+1}\right)^2}{\left(x-1\right)^4}}\)