Tentukan nilai p agar barisan (2p - 1); 6p : (20p + 8 ) membentuk barisan geometri!

6p/(2p-1) = (20p +8)/6p
(6p)² = (2p-1)(20p+8)
36p² = 40p² -20p + 16p -8
36p² - 40p² +4p +8 = 0
-4p² + 4p + 8 = 0
p² -p -2 = 0
(p-2)(p+1) = 0
p-2 = 0

p = 2