•Given 7 - 8 = -1
• -[-7 + 8] = -1, This choice
• 0 - 7 + (-8) = -15
• 7? + -8 = -1, This choice (if I understand “07” correctly)
• -7 + 8 = 1
Both are not functions because functions cannot have repeating x values
Answer with positive exponent =
or 
Answer with negative exponent = 
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Explanation:
The rule we use is

If we multiply two exponential expressions with the same base, then we add the exponents.
The base for each is 5. The exponents 4 and -7 add to -3.
This means

To convert to a positive exponent, we apply the reciprocal to the base. We go from 5, aka 5/1, to 1/5.
So, 
Answer: D.
Step-by-step explanation:
The distributive property is when you distribute the numbers to make solving easier. This means getting rid of the parentheses. SO your answer would either be A or D.