...|--2O--.--2O--|

...|......../ \........|

10V..4O 4O..10V

...|.../ .......... \ ..|

...|./___R5___\.|

(...) are only to space, no circuit is there!

I'm looking for the equations, but only get 5 independent and need 6.

So far,

I1=I3+I5 (junction lower left)

I4=I2+I5 (Lower right)

(i1+i2=i3+i4) <---- junction upper middle, but relation of the two above.

E1-R1*i1-R3*i3=0

-E2+R4*i4+R2*i2=0

-R4*i4-R5*i5+R3*i3=0

Can anyone help me out on this one? the answers are

i1=-15a

i2=25a

i3=-5a

i4=15a

i5=-20a

R5=4O

Thanks!!