Source transformation problem
In general you could use superposition** but in this case it's much simpler because the two supplies happen to end up being the same. 15V with 2\$\Omega\$  in series and 15V with 5\$\Omega\$ in series, which is equivalent to a single 15V supply with 5\$\Omega\$ || 2\$\Omega\$ =  1.43\$\Omega\$ in series, so the current is 15V/(1.43\$\Omega\$+7\$\Omega\$) = 1.78A

** Replace one voltage source with a short and calculate the current resulting from the other voltage source (1.27A), repeat with the other voltage source (0.51A). Add the two currents for the same result.