The expression that is not equivalent to 6³/(6^6) is; 1) 1/6²
The given expression is;
6³/(6^6)
x⁴/x² is equal to;
x^(4 - 2) = x²
Thus;
6³/(6^6) = 6^(3 - 6)
>> 6¯³
This can also be written as;
1/6³ or 1/216
Read more about laws of exponents at; https://brainly.com/question/18248071