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Write a rule for the nth term and find the 45th term for the arithmetic sequence with a10=1 and d = -6.

I have trouble with arithmetic sequences, could someone help me out?

This is all I have so far, which isn't much at all:
an = a1 + (n-1) d
an = a1 + (n-1)-6
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1 Answer

here is the correct way to write the formula for the nth term, when the constant difference d is negative 6:
an = a1 + (n-1)(-6)
 
When n=10, a10 = 1.  The prior term would be six more, because successive terms are 6 lower.
 
1 = a1 + (10-1)(-6) when n = 10; this allows you to solve for a1, which will be 55. 
 

Therefore an = 55 + (n-1)(-6)