Circuit Analysis In Exercises 69 and 70 , consider the circuit in the figure. The currents $I_{1}, I_{2},$ and $I_{3},$ in amperes, are given by the solution of the system of linear equations
$$\left\{\begin{aligned} 2 I_{1} &+4 I_{3}=E_{1} \\ I_{2}+4 I_{3} &=E_{2} \\ I_{1}+I_{2}-I_{3} &=0 \end{aligned}\right.$$
where $E_{1}$ and $E_{2}$ are voltages. Use the inverse of the coefficient matrix of this system to find the unknown currents for the voltages.
(GRAPH NOT COPY)
$$
E_{1}=10 \text { volts }, E_{2}=10
$$