Final answer:
The given Java code segment prints out 0.5 as a result of subtracting double y (2.5) from double x (3.0), after casting operations are performed on the values.
Step-by-step explanation:
The code segment in question involves casting and arithmetic operations in Java. The first line, double x = (int) (5.5 - 2.5);, involves casting the result of the subtraction, which is 3.0, to an integer, resulting in x being 3.0 because when a double is cast to an int, the decimal part is truncated.
The second line, double y = (int) 5.5 - 2.5;, first casts 5.5 to an int, resulting in 5, and then subtracts 2.5, ending with y equal to 2.5. The System.out.println(x - y); line prints out the result of the subtraction of y from x, which is 3.0 - 2.5, resulting in 0.5. Therefore, the output of the code segment is 0.5.