Add the following numbers in binary using 2's complement to represent negative numbers. Use a word length of 6 bits (including sign) and indicate if an overflow occurs. Repeat using 1's complement to represent negative numbers. (If overflow occurs, enter OVERFLOW.) (a) (-9) + (-6) 2's complement l's complement (b) (-9) + (-7) 2's complement 1's complement (c) (-8) + (-6) 2's complement 1's complement (d) 6 + 12 2's complement 1's complement (e) (-6) + (-13) 2's complement 1's complement