To find out the number of unique combinations of AK just multiply the amount of available aces by the amount of available kings.

1)There are 4 aces and 4 kings in the deck. 4x4 = 16
(therefore there are 16 combinations of AK possible)

If you hold an AK. There are 3 aces and 3 kings left in deck. 3x3 = 9
(therefore there are 9 combinations of AK still possible)

2) To find out suited combinations of AK. There are 4 Aces in the deck
but they can only be matched with one king. (the one of the same suit)
4x1=4 (therefore there are 4 suited combination of AK)

eg's.

- You have AhQs how many AQs are possible ?
3 aces are left but only 2 of them can be matched with a Queen of
the same suit. (so the answer is clearly 2 - without doing any maths)

- You have KhJh the flop is JdTd4d

1) How many KJ combinations are left? How many AJ combinations?
2) How many of them have tp and a flush draw?

1)Well there are 3kings left in the deck and 2 jacks. 3x2 =6
Therefore there are 6 combinations of KJ villian could hold.
There are 4aces left in the deck and 2 jacks. 4x2 = 8
Therefore there are 8 combinations of AJ villian could hold.

2) With KJ he has to hold Kd & there are 2 remaining Jacks. 1x2 =2
Therefore there are 2 combinations of KJ with a flush draw (KdJs;KdJc)
With AJ he has to hold Ad & there are 2 remaining Jacks. 1x2 = 2
Therefore there are also only 2 combinations of AJ with a flush draw
(AdJs; AdJc)

I dont know Im sure you can already do this Lukie and co it just seemed you were getting to the answer in a longer way.