Rút gọn biểu thức: A = √(x + 2√(2x - 4)) + √(x - 2√(2x - 4)), B = √(x - 2√(x - 1)) + √(x + 2√(x - 1)), C = √(3x + √(6x - 1)) + √(3x - √(6x - 1))

Rút gọn biểu thức:
A = sqrt(x + 2sqrt(2x - 4)) + sqrt(x - 2sqrt(2x - 4)) ;
B = sqrt(x - 2sqrt(x - 1)) + sqrt(x + 2sqrt(x - 1)) ;
C = sqrt(3x + sqrt(6x - 1)) + sqrt(3x - sqrt(6x - 1))