18. For each circuit in Figure 79, determine the Thevenin equivalent as seen from terminals A and B. 25 V (a) w 100 2 47 w w 2702 750 15 V (c) 10 V w 100 ww 56 kf ww RL 100 2 www OB ww 2700 B (b) 0.1A w 1.0 kf 2.2 km 2.2 k B w RL