x^2 - 6x + 13 = 0
uv = 13
(uv)^2 = u^2v^2 = 169
u + v = 6 square both sides
u^2 + 2uv + v^2 = 36
u^2 + 2(13) + v^2 = 36
u^2 + v^2 = 10
u^3 + v^3 = ( u + v) ( u^2 + v^2 - uv) = (6) ( 10 - 13) = -18
u / v^2 + v / u^2 =
[ u^3 + v^3 ] / [ u^2v^2 ] =
-18 / 169