(1)

Step 1:

Find the Nortons equivalent resistance.

1.Open the load resistor.

2.Open Current Sources and Short Voltage Sources.

3.Calculate the Open circuit Resistance.This is the Norton Resistance .

Step 2:

and are in series.

.

and are in series.

.

and are in parallel.

Nortons Resistance is .

Solution :

Nortons Resistance is .