Since x+4y = 8 the thing is y = 1/4*x but if you get 1/4 of x then multiply it by 4 when you put it back in the problem, which means x=4 y=1
Step-by-step explanation:
i think option a is the correct answer
Answer:

Step-by-step explanation:
We can write
as follows:
![\frac{11s}{s^2-12s+52}\\=11\left [ \frac{s}{s^2-12s+52} \right ]\\=11\left [ \frac{s}{(s-6)^2+16} \right ]\\=11\left [ \frac{s-6+6}{(s-6)^2+16} \right ]\\=11\left [ \frac{s-6}{(s-6)^2+16} \right ]+\frac{66}{(s-6)^2+16}](https://tex.z-dn.net/?f=%5Cfrac%7B11s%7D%7Bs%5E2-12s%2B52%7D%5C%5C%3D11%5Cleft%20%5B%20%5Cfrac%7Bs%7D%7Bs%5E2-12s%2B52%7D%20%5Cright%20%5D%5C%5C%3D11%5Cleft%20%5B%20%5Cfrac%7Bs%7D%7B%28s-6%29%5E2%2B16%7D%20%5Cright%20%5D%5C%5C%3D11%5Cleft%20%5B%20%5Cfrac%7Bs-6%2B6%7D%7B%28s-6%29%5E2%2B16%7D%20%5Cright%20%5D%5C%5C%3D11%5Cleft%20%5B%20%5Cfrac%7Bs-6%7D%7B%28s-6%29%5E2%2B16%7D%20%5Cright%20%5D%2B%5Cfrac%7B66%7D%7B%28s-6%29%5E2%2B16%7D)
To find:
![L^{-1}\left [ \frac{11s}{s^2-12s+52 \right ]}\\=L^{-1}\left [ 11\left [ \frac{s-6}{(s-6)^2+16} \right ]+\frac{66}{(s-6)^2+16} \right ]](https://tex.z-dn.net/?f=L%5E%7B-1%7D%5Cleft%20%5B%20%5Cfrac%7B11s%7D%7Bs%5E2-12s%2B52%20%5Cright%20%5D%7D%5C%5C%3DL%5E%7B-1%7D%5Cleft%20%5B%2011%5Cleft%20%5B%20%5Cfrac%7Bs-6%7D%7B%28s-6%29%5E2%2B16%7D%20%5Cright%20%5D%2B%5Cfrac%7B66%7D%7B%28s-6%29%5E2%2B16%7D%20%5Cright%20%5D)
We will use formulae:

we get solution as :
![L^{-1}\left [ 11\left [ \frac{s-6}{(s-6)^2+16} \right ]+\frac{66}{(s-6)^2+16} \right ]\\=L^{-1}\left [ 11\left [ \frac{s-6}{(s-6)^2+4^2} \right ]+\frac{66}{4}\left [ \frac{4}{(s-6)^2+4^2} \right ] \right ]\\=11e^{6t}\cos 4t+\frac{33}{2}e^{6t}\sin 4t](https://tex.z-dn.net/?f=L%5E%7B-1%7D%5Cleft%20%5B%2011%5Cleft%20%5B%20%5Cfrac%7Bs-6%7D%7B%28s-6%29%5E2%2B16%7D%20%5Cright%20%5D%2B%5Cfrac%7B66%7D%7B%28s-6%29%5E2%2B16%7D%20%5Cright%20%5D%5C%5C%3DL%5E%7B-1%7D%5Cleft%20%5B%2011%5Cleft%20%5B%20%5Cfrac%7Bs-6%7D%7B%28s-6%29%5E2%2B4%5E2%7D%20%5Cright%20%5D%2B%5Cfrac%7B66%7D%7B4%7D%5Cleft%20%5B%20%5Cfrac%7B4%7D%7B%28s-6%29%5E2%2B4%5E2%7D%20%5Cright%20%5D%20%5Cright%20%5D%5C%5C%3D11e%5E%7B6t%7D%5Ccos%204t%2B%5Cfrac%7B33%7D%7B2%7De%5E%7B6t%7D%5Csin%204t)
The speed of wind is 656 kmph and speed of plane is 70 kmph.
<u>SOLUTION:
</u>
Given that, an air-plane travels 4688 kilometers against the wind in 8 hours
And 5808 kilometers with the wind in the same amount of time.
We have to find the rate of the plane in still air and the rate of wind
Now, let the speed of wind be a kmph and speed of plane be b kmph.
And we know that, 

Substituting (1) in (2) we get,


On substituting (3) in (1) we get,

Hence, the speed of wind is 656 kmph and speed of plane is 70 kmph.