If it is a signed binary number with a length of one byte, then1001010/is a negative number, so use its complement.

Most significant bit is the sign bit. The original code is 0010101-1,and then the complement =111,with the symbol:1.

The decimal number is-(64+32+8+2+1) =-107.

If100101kloc-0/is an unsigned number,

Then,100101= hexadecimal 0x95 = decimal 9* 16+5 = 149.