Answer: Hi! the answer is D, now let's prove it:
Ok, let's analyze our problem; we know two facts:
1) the first day, the video has 143 likes
2) each day that pases, there are 3 times more likes.
this means, that the day 1, the video has 143 like, the day 2, has 3*143 = 429 likes, the day 3, it has 3*429 = 1287
now, this is f(n) = the number 143 multiplied by 3 (n - 1) times, where n is the amount of days.
the function that describes this is f(n) =
when n = 1, f(1) = = 143
when n = 2, f(2) = = 143*3
and so on, so the correct answer is D.
Also you can check the other functions if you like:
A) c(1) = (3)(143)^{1-1} = 3, so A doesn't work for the first day.
B) c(1) = 143^{1-1} = 1, B neither works for the first day.
C) c(1) = (3)143 − 1 = 428. C neither works for the first day