I guess 26 first question ...
Answer: 
; 5
Step-by-step explanation:
Given series : ![[\dfrac{5}{1\cdot2}]+[\dfrac{5}{2\cdot3}]+[\dfrac{5}{3\cdot4}]+....+[\dfrac{5}{n\cdot(n+1)}]](https://tex.z-dn.net/?f=%5B%5Cdfrac%7B5%7D%7B1%5Ccdot2%7D%5D%2B%5B%5Cdfrac%7B5%7D%7B2%5Ccdot3%7D%5D%2B%5B%5Cdfrac%7B5%7D%7B3%5Ccdot4%7D%5D%2B....%2B%5B%5Cdfrac%7B5%7D%7Bn%5Ccdot%28n%2B1%29%7D%5D)
Sum of series = ![S_n=\sum^{\infty}_{1}\ [\dfrac{5}{n\cdot(n+1)}]=5[\sum^{\infty}_{1}\dfrac{1}{n\cdot(n+1)}]](https://tex.z-dn.net/?f=S_n%3D%5Csum%5E%7B%5Cinfty%7D_%7B1%7D%5C%20%5B%5Cdfrac%7B5%7D%7Bn%5Ccdot%28n%2B1%29%7D%5D%3D5%5B%5Csum%5E%7B%5Cinfty%7D_%7B1%7D%5Cdfrac%7B1%7D%7Bn%5Ccdot%28n%2B1%29%7D%5D)
Consider 
⇒ ![S_n=5\sum^{\infty}_{1}\dfrac{1}{n\cdot(n+1)}=5\sum^{\infty}_{1}[\dfrac{1}{n}-\dfrac{1}{n+1}]](https://tex.z-dn.net/?f=S_n%3D5%5Csum%5E%7B%5Cinfty%7D_%7B1%7D%5Cdfrac%7B1%7D%7Bn%5Ccdot%28n%2B1%29%7D%3D5%5Csum%5E%7B%5Cinfty%7D_%7B1%7D%5B%5Cdfrac%7B1%7D%7Bn%7D-%5Cdfrac%7B1%7D%7Bn%2B1%7D%5D)
Put values of n= 1,2,3,4,5,.....n
⇒ 
All terms get cancel but First and last terms left behind.
⇒
Formula for the nth partial sum of the series :
Also, 
Answer:
Rotate 180 degrees with the center the origin (0,0)
Step-by-step explanation:
Try drawing a small square in the first quadrant, then reflect it like the direction. If you use tracing paper and and copy the figure, you will see that if you rotate the figure at the origin, it will land on the same spot as the translations.
The perimeter is equal to 60 feet and has the formula:
Perimeter = 2 l + 2 w
60 = 2 l + 2 w
The area is equal to 200 square feet and has the formula:
Area = l w
200 = l w
Rewriting area in terms of l:
l = 200 / w
Combining this with the perimeter formula:
60 = 2 (200 / w) + 2 w
60 = 400 / w + 2 w
Multiplying all by w:
60 w = 400 + 2 w^2
Dividing by 2 and rearranging:
w^2 – 30 w = - 200
Completing the square:
(w – 15)^2 = - 200 + (-15)^2
(w – 15)^2 = 25
w – 15 = ±5
w = 10, 20
Hence the dimensions of the garden is 10 feet by 20 feet
