Q4) a) Design and sketch a 4 bit sign - magnitude binary subtractor to subtract B[B3B2B1B0] from A[A3A2A1A0] by using only minimum number of 4 bit binary adders and suitable gates b) Use minimum number of components and Explain evey step of the operation for your subtractor. (4 bit binary adder is shown below) A3 A2 A1 A0 B3 B2 B Bo 4 BIT BINARY ADDER Cout S3 S2 S1 So Cin Show working wherever possible. Stick to the variable names given in the question. Problem 1) Perform the following binary addition, 210 +310- Create an adder/subtractor circuit capable of the above arithmetic. 2) Perform the following binary addition, 710 + 1110- Create an adder/subtractor circuit capable of the above arithmetic. 3) Perform the following binary subtraction, -710-310- Create an adder/subtractor circuit capable of the above arithmetic. 4) Perform the following binary subtraction, 610 - 1610 Create an adder/subtractor circuit capable of the above arithmetic.