Question

What is the 35th term of the arithmetic sequence where a1=13 and a17=-51

Answer 1

Arithmetic sequences have constant differecne so a17-a1=-64

17 - 1 = 16, so you know how many terms are there between the two given, so the difference in two consecutive terms is -64/16=-4

If you want to know to a35 from a17 you know there are, 35-17=18, terms, just
-4*18=-72

Then a35=a17-72=-51-72=-123

Answer 2

Thank you that is a great help and your explaination really helped me to understand

Answer 3

Yw (: