Answer:
A, and D
Step-by-step explanation:
A works because when you multiply like bases, you add exponents, so we have...
5^7*5^-4 = 5^(7+(-4)) = 5^(7 -4) = 5^3
B doesn't work because when you divide like bases, you subtract the exponent of the denominator from the exponent of the denominator...
5^12/5^4 = 5^(12 - 4) = 5^8
C doesn't work because there is addition.
5 + 5² = 5 + 25 = 30, and 5³ = 125
D works because 5^0 = 1, so we have
5^0(5^3) = 1(5^3) = 5^3
E doesn't work because there is subtraction...
5^3 - 5^0 = 5^3 - 1 = 124
