Answer:
5/4
Explanation:
You want the product abc when 5x^-2y^(3/2)/√(25xy^4) is written as ax^by^c.
Rules of exponents
The applicable rules of exponents are ...

Application
Using these rules, the expression can be simplified to ...

From this last expression, we determine ...
Product
The product of the values of interest is ...
abc = (1)(-5/2)(-1/2)
abc = 5/4