Answer:
a) -7/9
b) 16 / (n² + 15n + 56)
c) 1
Step-by-step explanation:
When n = 1, there is only one term in the series, so a₁ = s₁.
a₁ = (1 − 8) / (1 + 8)
a₁ = -7/9
The sum of the first n terms is equal to the sum of the first n−1 terms plus the nth term.
sₙ = sₙ₋₁ + aₙ
(n − 8) / (n + 8) = (n − 1 − 8) / (n − 1 + 8) + aₙ
(n − 8) / (n + 8) = (n − 9) / (n + 7) + aₙ
aₙ = (n − 8) / (n + 8) − (n − 9) / (n + 7)
If you wish, you can simplify by finding the common denominator.
aₙ = [(n − 8) (n + 7) − (n − 9) (n + 8)] / [(n + 8) (n + 7)]
aₙ = [n² − n − 56 − (n² − n − 72)] / (n² + 15n + 56)
aₙ = 16 / (n² + 15n + 56)
The infinite sum is:
∑₁°° aₙ = lim(n→∞) sₙ
∑₁°° aₙ = lim(n→∞) (n − 8) / (n + 8)
∑₁°° aₙ = 1
Hi!




Explanation: <u><em>This question is super super easy to me. This question is about how to use their order of operations the math problems. First you had to used PEMDAS stands for P-Parenthesis first, E-Exponents second, M-Multiply third, D-Divide fourth, A-Add fifth, and S-Subtract sixth. Then multiply and divide from left to right with 6*7=42. Then 27*9=243,42-243+64, and add or subtract from left to right with 42-243+64=-137 is the right answer. Hope this helps! And thank you for posting your question at here on Brainly. And have a great day. -Charlie</em></u>
Step-by-step explanation:
Given
If x = 4 Then
3x + 1 = 3 * 4 +1 = 12 + 1 = 13
The answer should be 13.
Answer:
x=11(12y-15)
Step-by-step explanation:
4x(3y-2)=7x+11
12xy-8x=7x+11
12xy-8x-7x=11
12xy-15x=11
x(12y-15)=11
x(12y-15)/(12y-15)=11/(12y-15)
x=11/(12y-15)