An 8x1 multiplexer is a digital switch that selects one of eight input signals and forwards it to a single output based on a 3-bit selection input.
A 4-bit full adder/subtractor is a circuit that adds or subtracts two 4-bit binary numbers.
It uses a control signal to choose between addition and subtraction.
The circuit gives a 4-bit result and a carry or borrow bit.
A 4x1 multiplexer is a device that selects one of four input signals to send to a single output.
It uses two select lines to choose which input to transmit.