177k views
0 votes
What is the 5th term of an arithmetic sequence if t3 = 10 and t7 = 26

1 Answer

3 votes
t 1 + 2 d = 10 / * ( - 1 )
t 1 + 6 d = 26
-------------------
- t 1 - 2 d = - 10
+
t 1 + 6 d = 26
---------------------
4 d = 16, d = 4
t 1 + 8 = 10
t 1 = 2
t 5 = t 1 + 4 d = 2 + 4 * 4 = 2 + 16 = 18
Answer: the 5th term of this sequence is 18.
User Tsume
by
8.1k points