Representation of Signed integer in 2's complement form:

Consider the eight bit number 01011100, 2's complements of this number is 10100100. If we perform the follwoing addition:

Since we are considering an eight bit number, so the 9th bit (MSB) of the result can not be stored. Therefore, the final result is 00000000.

Since the addition of two number is 0, so one can be treated as the negative of the other number. So, 2's complement can be used to represent negative number.