
This is a mensa question.
The given solution is that the first number in a row multiplied by the second gives the last two rows:
9*2=18
6*4=24
5*7=35
8*8=64
However, it looks like you can also subtract the first from the second row then add it to the third to get the fourth:
(9-2)+1=8
(6-4)+2=4
...