Answer:
1.) the answer is the fourth one, 1/5^7
2.) the answer is the fourth one, 1/5^6
3.) the answer is the fourth one, (2^6)^-5
4.) this is seems to be a duplicate of the first one
Explanation:
1.) by 'adding' 4 exponent values on the top it simplifies the top to simply one and 5^7 on the bottom
2.) since this is an exponent of an exponent multiply them, getting 5^-6, then simplify negative exponents.
3.) exponents of exponents are multiplied