With two's complement signed binary representation, what is the range of numbers as written in binary and in decimal for an eight-bit cell? (lowest to highest)

Convert -7 from base ten representation to its equivalent excess eight in binary form:

Convert -58 from decimal to binary, assuming seven-bit twos complement binary representation:

With unsigned binary representation, what is the range of numbers as written in binary and in decimal for an eight-bit cell? (lowest to highest)

What decimal number is represented by the following excess 8 notation?

0000