Electricity: Kirchhoff's Rules An application of Kirchhoff's Rules to the circuit shown below results in the following system of equations:
$$
\left\{\begin{aligned}
I_{2} &=I_{1}+I_{3} \\
5-3 I_{1}-5 I_{2} &=0 \\
10-5 I_{2}-7 I_{3} &=0
\end{aligned}\right.
$$
Find the currents $I_{1}, I_{2}$, and $I_{3}$.