SOLUTION: The second term of an arithmetic sequence is 18 and the 9th term is 46. Find the first term.

Algebra ->  Sequences-and-series -> SOLUTION: The second term of an arithmetic sequence is 18 and the 9th term is 46. Find the first term.      Log On


   

Question 822257: The second term of an arithmetic sequence is 18 and the 9th term is 46. Find the first term.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The second term of an arithmetic sequence is 18 and the 9th term is 46. Find the first term.
--------------------
Equations:
2nd term:: a + d = 18
9th term:: a +8d = 46
--------
Subtract and solve for "d"::
7d = 28
d = 4
-----
Solve for "a":
a + d = 18
a + 4 = 18
a = 14 (1st term)
=======================
Cheers,
Stan H.
=======================