Question

Need help with signed, 1's, and 2's compliments problems. Info in comment.

Answer 1

I'm pretty lost when it comes to this stuff. I just need someone to help me through these, not outright answers.

Answer 2

1-> Positve number are written as is in their equivalent binary form.
2-> Negative numbers are written in 3 available form - Sign Magnitude, 1's complement, 2's Complement form.

So +8 = 0 0000 0100 (0 = sign bit, rest is 7 binary bits of 8) ... in all notation
-8 = 1 0000 0100 (1 = sign bit of -ve number, rest is as is binary value of 8)
= 1 1111 1011 (1 = sign bit, rest is 1's complement of binary value of 8)
= 1 1111 1100( 1= sign bit, rest is 2's complement of the binary value of 8)

1's complement = complement each bit of given number.
2's complement = 1's complement + 1.

given say = 0100
1's complement = 1011
2's complement = 1011 + 1 = 1100

Now try the problems!!!

Answer 3

2's complement of (2's complement) = same number
as not(not A) = A ...likewise

Answer 4

I got all but -17. Can you help with that one?

Answer 5

17 = 0001 0001
-17 = 1110 1110 in 1's complement = 1110 1111 in 2's complement
-(-17) = 1's complement of 1110 1110 = 0001 0001 = +17
= 2's complement of 11101111 = 0001 0001 = +17