Answer:
2
Step-by-step explanation:
since they are similar
they will be divided by 9 for example
we have 54 on the left but if you divide it by 9 we get 6 which is on the right
then we have 27 on the left if you divide by 9 we get 3 which is on the right
so then we have 18 and a missing number
so we divide 18/9 and get 2
