Solve[{
Subscript[v,R1] == Subscript[i,R1] * Subscript[R,1],
Subscript[v,R2] == Subscript[i,R2] * Subscript[R,2],
Subscript[v,R3] == Subscript[i,R3] * Subscript[R,3],
Subscript[v,R4] == Subscript[i,R4] * Subscript[R,4],
Subscript[v,R5] == -Subscript[I,2] * Subscript[R,5],
Subscript[v,R2] + Subscript[v,R1] - Subscript[V,1] == 0,
Subscript[v,R3] + Subscript[v,R4] + Subscript[v,I1] - Subscript[v,R2] == 0,
Subscript[v,R5] + Subscript[v,I2] - Subscript[V,R4] == 0,
Subscript[i,R1] - Subscript[i,R2] - Subscript[i,R3] == 0,
Subscript[i,R3] + Subscript[I,2] - Subscript[i,R4] == 0,
Subscript[i,R4] - Subscript[I,2] - Subscript[I,1] == 0
},{
Subscript[v,R1],
Subscript[v,R2],
Subscript[v,R3],
Subscript[v,R4],
Subscript[v,R5],
Subscript[v,I1],
Subscript[v,I2],
Subscript[i,R1],
Subscript[i,R2],
Subscript[i,R3],
Subscript[i,R4]
}]
