Answer:Hint:
the remainder is 2.
Step-by-step explanation:
23≡1 mod 7 and 33≡−1 mod 7.
Edit: The only thing you need from the modular arithmetic is that
a⋅b mod 7=(a mod 7)(b mod 7) mod 7,
meaning the remainder of a product is the remainder of the product of remainders. This is self-evident as a⋅b must have the same remainder as (a−7k)⋅(b−7l).
Since exponentiation is just repeated multiplication, we can write
230⋅320=(23)10⋅(33)6⋅32≡110⋅(−1)6⋅9=9