Subtraction of 01000-01001 using 2's complement method.
Ans. Firstly 1's complement of 01001 is 10110 and 2's complement is 10110+ 1 =10111.
Thus
01000 = 01000
- 01001 = +10111 (2's complement)
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11111 (Summation)
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Because the MSB of the sum is 1, that means the result is negative and this is in 2's complement form. Therefore, 2's complement of 1111 =00001= (1)10. Thus, the result is - 1.