Answer: tn = -5n + 24 or tn = 19 - 5(n - 1)
Step-by-step explanation: The first formula:
The first term is 19 and the second is 14 so the common difference is -5
Then multiply -5 by 1 (first term) which is -5 and found the number we should add is 24 (This is the way i found myself, the formula people usually use is the second one)
The second formula:
tn = t1 + (n - 1) d
tn = 19 - 5(n - 1)
Because the common difference is -5 so the plus symbol will be changed into minus.