Solution
1). Calculate the current intensity Ix
Redraw the circuit for the ;opp analysis,

Apply KCL at node A.
I1+Ix=1.5Ix
I1=0.5Ix (1)
Redraw the circuit for the ;opp analysis,

Apply KVL in both mesh.
−6−5I1+3Ix+4Ix=0
From equation (1) :
−6−5(0.5Ix)+3Ix+4Ix=0
−6−2.5Ix+3Ix+4Ix=0
−6+4.5Ix=0
4.5Ix=6=>Ix=4.56=1.33A
2). Générateur de Thévenin entre les bornes 𝑎−𝑏
For Eth
Eth=4Ix
=4(4.56)=5.33V
To calculate Isc , short the terminal a-b , The circuit would be drawn as,

Apply KVL in large loop .
−6−5I1+3Isc=0
Form equation (1) :
−6−5(0.5Ix)+3Isc=0
−6−2.5Isc+3Isc=0
0.5Isc=6=>Isc=0.56=12A
Now, calculate Rth
Rth=IscEth=125.33=0.44Ω
1). Thus, Ix=1.33A
2). Thus, Eth=5.33V & Rth=0.44Ω