The answer to your question is 260(cm2)
The tree died 3696 years ago because 66x5600=369600/10=3696.
The mean of 5 and 15 is 10. (5+15= 20 20/2=10)
Answer:
D. 84 square feet
Step-by-step explanation:
Hope this helps and have a nice day
Answer:
![S_{10}=280](https://tex.z-dn.net/?f=S_%7B10%7D%3D280)
Step-by-step explanation:
Given that,
...(1)
We need to find the value of
.
Put n = 1 to find the first term.
![t_1=2(1)+3=5](https://tex.z-dn.net/?f=t_1%3D2%281%29%2B3%3D5)
Put n = 2 to find the second term.
![t_2=2(2)+3=7](https://tex.z-dn.net/?f=t_2%3D2%282%29%2B3%3D7)
Put n = 3 to find the third term.
![t_3=2(3)+3=9](https://tex.z-dn.net/?f=t_3%3D2%283%29%2B3%3D9)
Put n = 10 to find the tenth term.
![t_{10}=2(10)+3=23](https://tex.z-dn.net/?f=t_%7B10%7D%3D2%2810%29%2B3%3D23)
It means we need to find the sum of 5,7,9,.....,23.
The formula for the sum of n terms is given by :
![S_=\dfrac{n}{2}(a+a_n)](https://tex.z-dn.net/?f=S_%3D%5Cdfrac%7Bn%7D%7B2%7D%28a%2Ba_n%29)
We have, n = 10, a = 5 and ![a_n=23](https://tex.z-dn.net/?f=a_n%3D23)
So,
![S=\dfrac{10}{2}(5+23)\\\\S_{10}=10\times 28\\\\=280](https://tex.z-dn.net/?f=S%3D%5Cdfrac%7B10%7D%7B2%7D%285%2B23%29%5C%5C%5C%5CS_%7B10%7D%3D10%5Ctimes%2028%5C%5C%5C%5C%3D280)
So, the value of
is equal to 280.