# Series of partial sums

#### gkamal

1. Homework Statement 2. Homework Equations

an= bn - bn+1 which is already in the problem

3. The Attempt at a Solution

i did partial fractions but then i got stuck at

16/12 [4n-5] - 16/12 [4n+7] that part about bn confuses me please someone explain in detail

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#### Mark44

Mentor
1. Homework Statement 2. Homework Equations

an= bn - bn+1 which is already in the problem

3. The Attempt at a Solution

i did partial fractions but then i got stuck at

16/12 [4n-5] - 16/12 [4n+7] that part about bn confuses me please someone explain in detail
Where's the equation you're working with?
Starting from $\frac{16}{16n^2 + 8n - 35} = \frac{A}{4n - 5} + \frac{B}{4n + 7}$, multiply both sides by $16n^2 + 8n - 35$ to clear out all of the denominators. Then solve for the constants A and B.

#### gkamal

i did and i get 16/12 for A and - 16/12 for B as i indicated above the problem is what is the next step

#### vela

Staff Emeritus
Science Advisor
Homework Helper
Education Advisor
I think there's a typo in the problem. It should say $a_n = b_n - b_{n+3}$.

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