#sqrt((729x^(3/4))^(1/3))#
#sqrt((729^(1/3) xx x^(3/4 xx 1/3))#
#sqrt((729^(1/3) xx x^(cancel3/4 xx 1/cancel3))#
#sqrt(729^(1/3) xx x^(1/4))#
#sqrt((27^2)^(1/3) xx x^(1/4))#
#sqrt(27^(2 xx 1/3) xx x^(1/4))#
#sqrt(27^(2/3) xx x^(1/4))#
Recall #-> sqrta = a^(1/2)#
#rarr (27^(2/3) xx x^(1/4))^(1/2)#
#rArr (27^(2/3 xx 1/2) xx x^(1/4 xx 1/2))#
#rArr (27^(cancel2/3 xx 1/cancel2) xx x^(1/8))#
#rArr (27^(1/3) xx x^(1/8))#
#rArr ((3^3)^(1/3) xx x^(1/8))#
#rArr (3^(3 xx 1/3) xx x^(1/8))#
#rArr (3^(cancel3 xx 1/cancel3) xx x^(1/8))#
#rArr (3^1 xx x^(1/8))#
#rArr 3x^(1/8)#