Final answer:
A computer with a word length of 8 bits can represent numbers from -128 to +127 in 2's complement, and from -127 to +127 in 1's complement due to the existence of negative zero.
Step-by-step explanation:
A computer with a word length of 8 bits can represent a range of numbers using either 2's complement or 1's complement for negative numbers. In 2's complement, the range of numbers that can be represented is from -128 to +127. In the case of 1's complement, the range is from -127 to +127, as 1's complement allows for a negative zero which uses up one representation. A computer with a word length of 8 bits (including sign) can store a range of numbers using 2's complement or 1's complement.
With 2's complement, the range of numbers that can be stored is from -128 to 127. The leftmost bit is used to represent the sign, with 0 indicating a positive number and 1 indicating a negative number. The remaining 7 bits represent the magnitude of the number.
With 1's complement, the range of numbers that can be stored is from -127 to 127. The leftmost bit is still used for the sign, but the remaining 7 bits represent the magnitude of the number using the 1's complement representation.