7^4 x 7 x 7^13 x 7^-20
To simplify this expression, we can combine the powers of 7.
The rule for multiplying powers with the same base is to add the exponents.
Therefore, 7^4 x 7 x 7^13 x 7^-20 can be simplified as:
7^(4+1+13-20) = 7^(-2)
So, 7^4 x 7 x 7^13 x 7^-20 is equivalent to 7^(-2) or 1/49.