Question

Can anyone help including explaining how it was done ....Sign extend the two-digit hex number 97 to a four-digit hex number is???

Answer 1

Hex(97) = Binary (1001,0111)

Now to account for sign, we need to add a whole byte (smallest unit)
Positive : Binary(0000,0000,1001,0111) = Hex(0097)

That's ^^ the only possible explanation I could think for 4-digit Hex