Answer:
a) 72
b) 85
c) -86
Explanation:
A 2's-complement numbers is converted to decimal form by multiplying each instance of 1 by 2^(position -1) and adding the sub-results.
a) 01001000 =>
1* 2^(7-1) + 1*2^(4-1) = 64+8 = 72
b) 01010101 =>
1* 2^(7-1) + 1*2^(5-1) + 1*2^(3-1) + 1*2^(1-1) = 64+16+4+1 = 85
c) 10101010
1's complement of the given number by bit inversion is 01010101
2's complement is obtained by adding 1 to the 1's complement.
=01010110
In decimal this is : 1*2^(7-1)+1*2^(5-1)+1*2^(3-1)+1*2^(2-1) = 64+16+4+2 = 86
So the original number is negative of this = -86
