First, use these rules for exponents to eliminate the outer exponent:
a = a^color(red)(1) and (x^color(red)(a))^color(blue)(b) = x^(color(red)(a) xx color(blue)(b))
(25x^(-1/2)y^(2/2))^(1/2) => (25^color(red)(1)x^color(red)(-1/2)y^color(red)(2/2))^color(blue)(1/2) => 25^(color(red)(1)xxcolor(blue)(1/2))x^(color(red)(-1/2)xxcolor(blue)(1/2))y^(color(red)(2/2)xxcolor(blue)(1/2)) =>
25^(1/2)x^-1/4y^(2/4) => 25^(1/2)x^(-1/4)y^(1/2)
We can now use this rule for exponents/radicals to evaluate the constant:
x^(1/color(red)(n)) = root(color(red)(n))(x)
25^color(red)(1/2)x^(-1/4)y^(1/2) => sqrt(25)x^(-1/4)y^(1/2) => 5x^(-1/4)y^(1/2)
Next, we can use this rule for exponents to eliminate the negative exponent:
x^color(red)(a) = 1/x^color(red)(-a)
5x^color(red)(-1/4)y^(1/2) => (5y^(1/2))/x^-color(red)(-1/4) => (5y^(1/2))/x^(1/4)