1.

13 = D (hexadecimal)    13 = 1101 (binary)
468 = 1D4 (hexadecimal)   468 = 111010100 (binary)

2.

-108 = 10010011 (1's complement)   -108 = 10010100 (2's complement)
-55 = 11001000 (1's complement)   -55 = 11001001 (2's complement)

3.

  79 = 01001111      68 = 01000100
 -55 = 11001001  -115 = 10001101
           -----------              -----------
          00011000              11010001

Both integers (235, 142) are out of range, 2's complement addition is meaningless

The minuend (150) is out of range so 2' s complement addition is meaningless.

4.

1677 = 0000011010001101
1078 = 0000010000110110 ( - )
            -----------------------
            0000001001010111 (by binary subtraction)

  1677 = 0000011010001101
-1078 = 1111101111001010 ( + ) (2's complement)
              -----------------------
              0000001001010111 (by 2's complement addition)

NEXT PAGE -------- >>>> HERE

EL10B Homepage