Final answer:
To perform binary subtraction of (28)₂ - (15)₂ using 2's complement representation, first calculate the 2's complement of the second number by inverting bits and adding 1. Then, add the first number with the 2's complement of the second number. Remove the most significant bit if necessary to obtain the final answer.
Step-by-step explanation:
To perform binary subtraction using 2's complement representation, we first need to calculate the 2's complement of the second number. In this case, the 2's complement of (15)₂ would be (11100001)₂. Next, we can add the first number (28)₂ with the 2's complement of the second number: (28)₂ + (11100001)₂. The result is (110010101)₂. Since we are representing the numbers in 8 bits, we can remove the most significant bit (1) since it represents the negative sign in 2's complement representation. Therefore, the final answer is (10010101)₂, which is equivalent to (-11)₂ in signed decimal representation.