we have that
26*[(82³)^(1/2)]*[(62³)^(1/2)]
we know that
(82³)^(1/2)-----> 82√82
(62³)^(1/2)-----> 62√62
substitute
26*[82√82]*[62√62]------> (26*82*62)*(√82)*(√62)
(26*82*62)*(√82)*(√62)------> 132184*(√82)*(√62)
132184*(√82)*(√62)------> 132184*(√5084)
5084------> 1271*2²
√5084-----> √(1271*2²)-----> 2√1271
substitute
132184*(√5084)------> 132184*(2√1271)-----> 264368√1271
the answer is
264368√1271