I have a problem with writing net ionic equations...?

Question

Especially this one.

Solutions of cobalt(II) nitrate and potassium hydroxide are mixed. I got this answer but my teacher says it is wrong... any ideas?
Co(NO3)2 (aq) + 2 KOH- (aq) > Co(OH)2 (s) + 2 KNO3 (aq)

Answer 1

Look at the ions which change state:

Co2+(aq) + 2OH-(aq) -----> Co(OH)2(s)

The spectator ions are K+ and (NO3)-, and are left out.