Explanation:
(1/6²)⁵ = 1/6¹⁰ = 6^-10
because in the case of exponent of an exponent the exponents are multiplied with each other.
and 1/n = n^-1
(6^-5)² = 6^-10
because as above the exponents are multiplied with each other.
6^-3 / 6⁷ = 6^(-3 - 7) = 6^-10
a^n × a^m = a^(n+m)
a^n / a^m = a^(n-m)
the others are not 6^-10 :
6^-5 × 6² = 6^(-5 + 2) = 6^-3
6⁵×6^-3 / 6^-8 = 6^(5 - 3 - -8) = 6^(5 ‐ 3 + 8) = 6¹⁰