
Spendthrift Sam and Thrifty Teri each have bank accounts. Currently Sam has $500, while Teri has $200.

Every Friday afternoon Sam withdraws $15; he wants to have some spending money when he goes out with his friends on Saturday evenings. At the same time Teri makes a deposit of $12; she is planning for a rainy day and wants to have a nice "nest egg" ready.
Use your TINspire™ to help you answer this question:
Use equations to show when their balances will be equal or as close as they will get.