SOLUTION: Find the common difference d for this sequence. 7,3,-1,-5,-9 Find a formula in simplest form, for the nth term a sub n for the sequence So, I know that the common difference

Algebra ->  Sequences-and-series -> SOLUTION: Find the common difference d for this sequence. 7,3,-1,-5,-9 Find a formula in simplest form, for the nth term a sub n for the sequence So, I know that the common difference       Log On


   

Question 1141342: Find the common difference d for this sequence. 7,3,-1,-5,-9
Find a formula in simplest form, for the nth term a sub n for the sequence
So, I know that the common difference is -4 but I do not know the formula.
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
Common Difference really, 4, but sequence is decreasing, not increasing.

7-4%28n-1%29


If you allow for a common difference to be negative, then:
7%2B%28-4%29%28n-1%29

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
Find the common difference d for this sequence. 7,3,-1,-5,-9
Find a formula in simplest form, for the nth term a sub n for the sequence
So, I know that the common difference is -4 but I do not know the formula.
Formula for specifc term of an AP: matrix%281%2C3%2C+a%5Bn%5D%2C+%22=%22%2C+a%5B1%5D+%2B+%28n+-+1%29d%29

                                    ------- Substituting matrix%282%2C3%2C+7%2C+for%2C+a%5B1%5D%2C+-+4%2C+for%2C+d%29