1. **State the problem:** Solve the system of linear equations: $$\begin{cases} 2I_1 - I_2 + 3I_3 + 4I_4 = 9 \\ I_1 - 2I_3 + 7I_4 = 11 \\ 3I_1 - 3I_2 + I_3 + 5I_4 = 8 \\ 2I_1 + I_2 + 4I_3 + 4I_4 = ? \end{cases}$$ Note: The last equation is incomplete; assuming it equals some constant $b$. Since it is missing, we cannot solve the system fully. Please provide the complete last equation. Since the last equation is incomplete, we cannot proceed to solve the system. Please provide the full last equation to continue.