Answer:
(a) P Â = Â - 200 T + 9,400
(b) After 22  months the student  will owe $5000.
Step-by-step explanation:
Here, the amount loaned out to the student = $9,400
The installment amount of each month  = $200
(a) P : Amount remaining to be paid
  T: time in months
Now, the remaining amount = Actual amount - Amount paid in T months
or, Â Â Â P = 9,400 - $200 (T)
⇒ P  =  - 200 T + 9,400 ( y = mx + C form)
(b) The remaining amount left = $5000
As we know, P = 9,400 - $200 (T)
⇒ 5,000 = 9,400 - 200 T
⇒200 T = 9,400 - 5,000 = 4,400
⇒ T = 4400/200 =  22
or T = 22 Months
Hence,  After 22  months the student  will owe $5000.