Answer:
For Kaisorn:

For Thom:

Explanation:
Each month, Kaisorn deposits $50.00 onto her public transportation card.
It costs her $2.50 per trip to ride the subway. Means 2.50x
Thom deposits $40.00 on his public transportation card. It costs him $2.00 per trip to ride the subway. Means 2x
Let x represents the number of trips
Let y represents the amount remaining in each account.
Then the system of equations represents their transportation costs are :
For Kaisorn:

For Thom:
