SOLUTION: Given that for an AP seventh term is equal to 43,nth term and 2nd term is equal to 91,find the valves of a,d and n

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Question 860692: Given that for an AP seventh term is equal to 43,nth term and 2nd term is equal to 91,find the valves of a,d and n
Found 2 solutions by ewatrrr, richwmiller:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

a%5B7%5D+=+a%5B1%5D+%2B+6+d+=+43

a%5B2%5D+=+a%5B1%5D+%2B++d++=+93

           5d = -50     |subtracting a2 from a7

            d = -10   and a%5B1%5D+=+103%0D%0A%7B%7B%7Ba%5Bn%5D+=+103+%2B+%28n-1%29%28-10%29

CHECKING our answer***

a%5B7%5D+=+103+-+60=+43

Wish You the Best in your Studies.

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
an = a + (n - 1)d
43 = a + 6d,
91 = a + d
-48=5d
a = 503/5, d = -48/5
The other tutor used 93 instead of the given 91