Solving for V0: KCL and KVL Methods in Electric Circuits

[qwerty321]

hello!
i have the circuit below and i need to determine V0 by using two methods:

1)apply KCL at node a and invoke KVL and OHM's law
2)transforming the voltage source to an equivalent current source that is combined with the 4mA source.

Ok let us begin with the 1)

applying kcl at node a gives:

4+i1-i2=0
then what next?

please help me
thank you

 

[Redbelly98]

Apply KVL to the 3 loops in the circuit.

 

[waht]

To simplify the circuit further what can you say about R4, R2, and R3?

 

[qwerty321]

the equivalent is equal to 5