Find all currents and voltages using Thevevin's theorem. Start by finding $I_3$ and $V_{R_3}$ in each case. Also drow the Thevenin equivalent of circuit to which $v_1=15v\frac{-1}{(\frac{?}{\text{b}\text{a}\text{r}}(T))}{R}_3$ is connected.

Fig. $10-43$