To find an equivalent expression with positive exponents, we can use the property of adding exponents when multiplying powers with the same base. In this case, we have 5^9 multiplied by 5^(-13).
Using the property, we can add the exponents: 5^(9 + (-13)).
Since adding a negative exponent is the same as subtracting the corresponding positive exponent, we get: 5^(-4).
Now, to convert this to a positive exponent, we can use the property of taking the reciprocal of a power. 1 / 5^(-4) is equal to 5^4.
Therefore, 5^9 multiplied by 5^(-13) is equivalent to 5^4.