Rút gọn biểu thức sau
a)A= 2 - x\(\sqrt{\frac{x}{x-2}+\frac{1}{x^2-4x+4}}\left(x>2\right)\)
b) B= \(\frac{2x}{x-2}\sqrt{5\left(x-2\right)^2}+\frac{\sqrt{45x^4}}{x}\left(x\ne0;x\ne2\right)\)
c) C= \(\frac{x-25}{x+5\sqrt{x}}+\sqrt{\frac{x-2\sqrt{x}+1}{x-10\sqrt{x}+25}}\left(x>0;x\ne5\right)\)