Answer: 8^7
The exponent 7 tells us how many copies of "8" are being multiplied together.
The expression 8*8*8 is equal to 8^3, while 8*8*8*8 = 8^4
Multiplying 8^3 and 8^4 will have us add the exponents to get 8^7. The base stays at 8 the entire time.
The rule is a^b*a^c = a^(b+c) where the base is 'a' the entire time.