For the circuit below, is = 10 A, R1 = 8.5 ΩΩ, R2 = 9 ΩΩ, and R3 = 17.5 ΩΩ. (a) Find the Thevenin equivalent of the network connected to ????????RL (b) Find the Norton equivalent of the network connected to ????????RL (c) Find voltage ????????vL using either of the equivalent circuits above if ????????RL = 31 ΩΩ. (d) Find voltage ????????vL if ????????RL = 41.5 ΩΩ.