The fifth term of an arithmetic sequence is 9 and the 32nd term is -84. What is the 23rd term?
The difference between 32nd term and 5th term is:
32 - 5 =27
The difference between the values of the two terms is:
-84 - 9 =-93, therefore their common difference is:
-93 / 27 =- 31/9, therefore the 1st term is:
[4 x 31/9] + 9 =22 7/9 =205/9, therefore:
23rd term=an = a1 + (n-1)d =205/9 + (23 -1)*-31/9=-53
