Need help on both parts please Which is also shown below and

Which is also shown below and answer next questions. The adder-subtractor is used to subtract the following unsigned 4-bit numbers: 0110 - 1010 (6 - 10). What arc the input binary values of A, B and M? Choose 3. A. 0110 B. 1010 C. 1 D. 0 E. 0101 In the preivous question, what are the output binary values of S and C_5? Choose two. A. 1100 B. 0100 C. 1011 D. 0 E. 1

Solution

9>

Since we are performing subtraction, the value of M should be 1.
Now looking at the diagram we can say that input A is not altered and fed to the added as it is, so we can conclude that A is minuend (ie. the +ve number) and B passes through XOR gates, therefore B is complemented so B is subtrahend (ie. the number that is substracted from minuend).
So A = 0110 and B = 1010

10> So we have:
      0110 - 1010
   = 0110 + 0101 + 1
   = 1100
Therefore S = 1100, Carry or C5 = 0.