Hi all,
I have to create a circuit with j-k flip flop(s),and multiplexer(s) which can calculate 2's complement.
I tried to use Cd4027 like an inverter( for 1's complement) and after that with the multiplexer to add 1.
I guess i have that inverter but i dont't know to to create an adder with 74LS151N
Thanks.

 

For school?
Reverse engineering a schematic from a photo of a breadboard is tedious and error prone. Please post a schematic.