Rút gọn biểu thức
1) x + 3 + \(\sqrt{x^2-6x+9}\) (x \(\le\) 3)
2) \(\sqrt{x^2+4x+4}-\sqrt{x^2}\) (-2 \(\le\) x \(\le\) 0)
3) \(\sqrt{x^{2^{ }}+2\sqrt{x^2-1}}-\sqrt{x^2-2\sqrt{x^2-1}}\)
4) \(\dfrac{\sqrt{x^2-2x+1}}{x-1}\) (x > 1)
5) |x - 2| + \(\dfrac{\sqrt{x^2-4x+4}}{x-2}\) (x < 2)
6) 2x - 1 - \(\dfrac{\sqrt{x^2-10x+25}}{x-5}\)