public class Program

{

    static (int, int) SimplifySign(int numerator, int denominator) 

    => (numerator, denominator) switch

    {

        ( < 0, < 0) => (-numerator, -denominator),

        ( > 0, > 0) => (-numerator, -denominator),

        _ => (numerator, denominator)

    };

    public static void Main()

    {

        var (x, y) = SimplifySign(1, 2);

    }

}