Answer:
![a = 18x](https://tex.z-dn.net/?f=a%20%3D%2018x)
Step-by-step explanation:
Given
![\frac{1}{2}(a + d) = 10x](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%28a%20%2B%20d%29%20%3D%2010x)
![\frac{1}{2}(b + c) = 8x](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%28b%20%2B%20c%29%20%3D%208x)
![\frac{1}{3}(b + c+d) = 6x](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B3%7D%28b%20%2B%20c%2Bd%29%20%3D%206x)
Required
The value of (a)
We have:
--- multiply by 2
--- multiply by 2
--- multiply by 3
So, we have:
![\frac{1}{2}(a + d) = 10x](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%28a%20%2B%20d%29%20%3D%2010x)
![a + d = 20x](https://tex.z-dn.net/?f=a%20%2B%20d%20%3D%2020x)
![\frac{1}{2}(b + c) = 8x](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%28b%20%2B%20c%29%20%3D%208x)
![b + c = 16x](https://tex.z-dn.net/?f=b%20%2B%20c%20%3D%2016x)
![\frac{1}{3}(b + c+d) = 6x](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B3%7D%28b%20%2B%20c%2Bd%29%20%3D%206x)
![b + c + d= 18x](https://tex.z-dn.net/?f=b%20%2B%20c%20%2B%20d%3D%2018x)
Substitute
in ![b + c + d= 18x](https://tex.z-dn.net/?f=b%20%2B%20c%20%2B%20d%3D%2018x)
![16x + d = 18x](https://tex.z-dn.net/?f=16x%20%2B%20d%20%3D%2018x)
Solve for d
![d = 18x - 16x](https://tex.z-dn.net/?f=d%20%3D%2018x%20-%2016x)
![d = 2x](https://tex.z-dn.net/?f=d%20%3D%202x)
Substitute
in ![a + d = 20x](https://tex.z-dn.net/?f=a%20%2B%20d%20%3D%2020x)
![a + 2x = 20x](https://tex.z-dn.net/?f=a%20%2B%202x%20%3D%2020x)
Solve for (a)
![a = 20x - 2x](https://tex.z-dn.net/?f=a%20%3D%2020x%20-%202x)
![a = 18x](https://tex.z-dn.net/?f=a%20%3D%2018x)
Step-by-step explanation:
hdvsjsbsddbsisbsbsibabs
Answer:
= 3n + 1 , n≥ 1
Step-by-step explanation:
The common difference of the sequence = 3 , so it is an arithmetic sequence.
The formula for the nth term of an arithmetic sequence is given as:
= a + (n-1)d
substituting the values of a and d , we have
= 4 + (n-1) X 3
= 4 + 3n - 3
= 1 + 3n
= 3n + 1 , n≥ 1
Answer: A
Step-by-step explanation:
The sum to infinity of a geometric series is
S (∞ ) = \frac{a}{1-r} ( - 1 < r < 1 )
where a is the first term 8 and r is the common ratio, hence
S(∞ ) = {8}{1-\{1}{2} } = {8}{1}{2} } = 16