Answer:
 6^8 = 1,679,616
Explanation:
The applicable rule of exponents is ...
 (a^b)^c = a^(bc)
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Applied to this problem, the rule tells you ...
 (6^2)^4 = 6^(2·4) = 6^8 = 1,679,616
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Or, you can evaluate the expression according to the Order of Operations:
 (6^2)^4 = 36^4 = 1,679,616