+0

# How many terms of the arithmetic sequence 88, 85, 82, . . . appear before the number -17 appears?

0
210
2

How many terms of the arithmetic sequence 88, 85, 82, . . . appear before the number -17 appears?

Guest Jul 20, 2017
Sort:

#1
+1

F + (N - 1)*D =Nth term.

88 + (N - 1)*-3=-17

88  -3N + 3 =-17

91 -3N = -17

-3N =-17-91

-3N = -108

N =-108 / -3

N = 36th term number with a value of -17. So, there are 35 terms before -17 appears.

Guest Jul 20, 2017
edited by Guest  Jul 20, 2017
#2
+82859
+1

Another way to determine this is to note that the difference between terms is 3

So.....to find out which term is -17, we have....

[ first term -  given term  ] / difference between terms + 1

[ 88 -  (- 17) ] / 3 +  1  =

[ 105 ] / 3 +  1  =

35 + 1

36

So, -17 is the 36th term  and 35 terms appear before it

CPhill  Jul 21, 2017

### 23 Online Users

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details