Answer: -105
Step-by-step explanation:
:)
A = 6
tn = a + (n - 1)d
t4 = 6 + 3d = 12
3d = 12 - 6 = 6
d = 6/3 = 2
f(n + 1) = f(n) + 2
3 to the 1st is 3
3 to the 2nd is 9
3 to the 3rd is 27
3 to the 4th is 81
3 to the 5th is 243
3 to the 6th is 729
I rounded it and the answer is 400