Answer:
Kay sold 6 boxes and Ayan sold 19 boxes
Explanation:
Let x = number of boxes Kay sells
y = number of boxes Ayan sells
Then the equations will be:

We can solve the system by using substitution method
Putting x = y-13 in equation 1

Dividing both sides by 2

Putting y = 19 in equation 2

Hence,
Kay sold 6 boxes and Ayan sold 19 boxes