[tex]E_1=3 V\\r_1=0,5\Omega\\R_4=2\Omega\\R_2=3\Omega\\R_3=3\Omega\\I_3=1A\\E_2=6V\\r_2=1\Omega\\E_1=I_2(R_4+r_1+R_3)+I_3R_2<=>3=I_2(2+0,5+3)+1*3<=>3=5,5I_2+3=>I_2=0\\E_2=I_3R_2-I_1(R_1+r_2)<=>6=1*3-I_1(R_1+1)<=>3=-I_1(R_1+1)\\I_2=I_1+I_3<=>0=1+I_1=>I_1=-1 A\\3=-I_1(R_1+1)<=>3=-(-1)(R_1+1)<=>3=R_1+1=>R_1=2\Omega[/tex]
