Binary Math computer science

Question

Complete Twos Compliment 8-bit Binary Math on the following expression: 25-68

Answer 1

Hello, Isaac C.

In 2s compliment, 8-bit binary, the (decimal) value 25 is 00011001, and 68 is 01000100. To subtract 68 (01000100) from 25 (00011001), we can take the 2s compliment of 68 (01000100), which is:

~(01000100) + 1 = 10111011 + 1 = 10111100 (which, in decimal, as a signed, 8-bit value, is -68)

and add it to 25 (00011001), so:

[phone])

+ -68 (10111100)

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-43 (11010101)