Question

the first term of a sequence is 12 and each term is 7 less than the last. what is the 25th term?

Answer 1

arithmetic sequence
\[a _{n} = a _{1} + d(n-1)\]
a1 = 12
d = -7
n = 25

Answer 2

thats what i was thought. thanks guys.

Answer 3

Oh ... My bad. The correct answer is:
n = 0, An = 12
n = 1, An = 12-7
n = 2, An = 12-7*2
...
n = 24, An = 12-7*24

Answer 4

diogo, usually with an arithmetic sequence the 1st term means n=1 Not n=0

Answer 5

if you start at n = 0, then n = 25 is really the 26th term

Answer 6

ah, nvm, you caught it. nice job :)