How do you do number 2? And what makes twos complement different from unsigned

155

Explanation:

Two's complement is basically switching all the numbers from 1 to 0 and from 0 to 1, and then adding 1 to the end.

2's complement of 01100101 = 10011010(switching numbers) + 1 = 10011011.

Then, you just convert this number to decimal, which can be done by adding the powers of 2:

1  0  0  1  1  0  1  1

128 + 16+8 +  2+1 = 155

Hope this helped.

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