number of Kian´s stamps=57+12x
number of Kai´s stamps=80+8x
x=number of months.
the number of Kian´s stamps must be the same than number of Kai´s stamps, so:
57+12x=80+8x
12x-8x=80-57
4x=23
x=23/4=5.75
The number obtained is decimal, therefore, they never will have the same number of stamps.
After 6 month, they will have almost similar numbers of stamps , but they never will have the same number of stamps.
Answer:they never will have the same number of stamps.