1/a - 1/3 = 1/(a-2)
Multiply by the LCD, 3a(a-2), to obtain: 3(a-2) - a(a-2) = 3a
3a - 6 - a2 + 2a = 3a
a2 - 2a + 6 = 0
a = [2 ± √(4-24)]/2 = [2 ± 2√5 i]/2 = 1 ± √5 i