Circuit solving problem from book of electronic please try also yourself

[marcofh]

pleaase help me to understand how to solve the circuit attached finding i.

thanks

 

[seadolphine2000]

Here you are the steps:
R1 = 2KOhm, R2 = 4KOhm, R3 = 10KOhm and, R4 = 5KOhm

1- R1//R2 = 4/3 KOhm
2- R3//R4 = 10/3 KOhm
3- Voltage across R1//R2 = V12 = 3mA * (R1//R2) = 4V
4- Voltage across R3//R4 = V34 = 3mA * (R3//R4) = 10V
5- i = (V12/R1) - (V34/R3) = (4/2KOhm) - (10/10KOhm) = 1 mA

 

[marcofh]

thanks!! great!