Answer: The answer is 1/2
Step-by-step explanation:
<h3>
<u>Correct Question :- </u></h3>


(a) 0
(b) 8000
(c) 8080
(d) 16000

Given that

We know


And


Also, given that


and

Now, Consider





![\sf \: = 20\bigg[ {a}^{2} + {b}^{2} + {c}^{2} + {d}^{2}\bigg]](https://tex.z-dn.net/?f=%20%5Csf%20%5C%3A%20%20%3D%2020%5Cbigg%5B%20%7Ba%7D%5E%7B2%7D%20%2B%20%20%7Bb%7D%5E%7B2%7D%20%2B%20%7Bc%7D%5E%7B2%7D%20%2B%20%20%7Bd%7D%5E%7B2%7D%5Cbigg%5D)
We know,

So, using this, we get
![\sf \: = 20\bigg[ {(a + b)}^{2} - 2ab + {(c + d)}^{2} - 2cd\bigg]](https://tex.z-dn.net/?f=%20%5Csf%20%5C%3A%20%20%3D%2020%5Cbigg%5B%20%7B%28a%20%2B%20b%29%7D%5E%7B2%7D%20-%202ab%20%2B%20%20%7B%28c%20%2B%20d%29%7D%5E%7B2%7D%20-%202cd%5Cbigg%5D)
![\sf \: = 20\bigg[ {( - 20)}^{2} + 2(2020) + {(20)}^{2} - 2(2020)\bigg]](https://tex.z-dn.net/?f=%20%5Csf%20%5C%3A%20%20%3D%2020%5Cbigg%5B%20%7B%28%20-%2020%29%7D%5E%7B2%7D%20%2B%20%202%282020%29%20%2B%20%20%7B%2820%29%7D%5E%7B2%7D%20-%202%282020%29%5Cbigg%5D)
![\sf \: = 20\bigg[ 400 + 400\bigg]](https://tex.z-dn.net/?f=%20%5Csf%20%5C%3A%20%20%3D%2020%5Cbigg%5B%20400%20%2B%20400%5Cbigg%5D)
![\sf \: = 20\bigg[ 800\bigg]](https://tex.z-dn.net/?f=%20%5Csf%20%5C%3A%20%20%3D%2020%5Cbigg%5B%20800%5Cbigg%5D)

Hence,

<em>So, option (d) is correct.</em>
Answer:
3/5
Step-by-step explanation:
Exact form
6(4-sqrt5)over 11
d.11