Complex system of equations



In a network analysis I have four complex relations about voltages, currents and
complex power (two KVL one KCL and s=v*conjugate(i)=P+jQ );   for example

(%i1) declare(ix,complex)$
(%i2) declare(iy,complex)$
(%i3) declare(v,complex)$
(%i3) declare(i,complex)$
(%i4) [va,vb,za,zb,s]:[5-%i,10,1+2*%i,1+%i,100+200*%i];
(%i5) e1:va-za*ix=v;
(%i6) e2:vb-zb*iy=v;
(%i7) e4:ix+iy=i;
(%i8) e4:v*conjugate(i)=s;
(%i9) solve([e1,e2,e3,e4],[ix,iy,v,i]);

but I get this error :(
"algsys: tried and failed to reduce system to a polynomial in one variable; give
up. -- an error. To debug this try: debugmode(true);"

How can i solve it ?

Thanks

Renzo