3. (6 marks) Evaluate the following expressions, in which each operand is an 8 bit 2 's complement number, using the standard binary addition algorithm (evaluate the subtraction in part (a) by negating then adding). As well as showing each result in 8 bit 2's complement, also convert and express each as a signed decimal number. Note that whenever there is signed overflow your answer will not be correct. For which expression(s) does this occur? (a) 1100010101000100 (b) 10101010+01110111 (c) 10111001+10001011