Find potential difference between nodes A and B in circuit below
Something tells me this question is abandoned by the author, but I'll give my view anyway as it's a funny one. I assume \$I_x=-I_z\$ and A is only connected to the \$8\,\Omega\$ and the \$6\, V\$ source, i.e.: crosses are no dots.
Then the 2 current sources are in parallel and their series resistors can be neglected, i.e.: there is a current source of \$10 \, A\$ connected from C to D.
From KVL \$8 \, \Omega I_x - 10 \, V - 8 \, \Omega I_y - 6 \, V = 0\$ and from KCL \$I_x + I_y = 10 \, A \$. In other words: 

$$ I_x = 10 \, A - I_y \, , \, I_x = 2 \, A +I_y $$
From subtracting the second from the first we have \$ 0 = 8 \, A -2I_y \$ so 
$$ I_y = 4\, A \, , \, I_x = 6\, A$$
making 
$$ U_A - U_B = 6 \, V + 8 \, \Omega I_x = 54 \, V $$