Answer:
1). 250 - 60t
2). 60t
Step-by-step explanation:
"Camila started her collection with 250 cards and decreased by 60 cards each year"
Starting number of cards with Camila = 250
Decrease in number of cards each year = 60
Decrease in number of cards after 't' years = 60t
Number of cards after 't' years = 250 - 60t
"Camila didn't have any card when she started her collection, but her collection grew by 60 cards each year."
Number of cards with Camila = 0
Number of cards grew each year = 60
Number of cards after 't' years = 60t + 0 = 60t