Answer:
20 hours
Step-by-step explanation:
We can work easier if we think in terms of an hour
the first equation that we can write is
A + B = 1/4 (its meaning is that in an hour A and B fill 1/4 of the cistern)
the second equation we can write is
A + C = 1/5 (its meaning is that in an hour A and C fill 1/5 of the cistern)
the third equation that we can write is
B = 2C (its meaning is that in an hour B fill 2 times C the cistern)
now we can substitute the value of B in the first two equations
A + 2C = 1/4
A + C = 1/5
A = 1/5 - C
1/5 - C + 2C = 1/4
C = 1/4 -1/5
C = (5-4)/20
C = 1/20 (this means that in an hour C will fill 1/20 of the cistern, so it takes 20 hours to fill the entire cistern)
A = 1/5 - 1/20
A = (4-1)/20 = 3/20
B = 1/20 *2 = 1/10
Answer: 20
Step-by-step explanation: Just took the quiz
-5i. is ur answer i think
Given:
The equation is:
To find:
The result of completing the square for the given equation.
Solution:
We have,
It can be written as:
Now, we need to add half of square of coefficient of x, to complete the square.
Adding 
on both sides, we get
![[\because (-a)^2=(a)^2]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%28-a%29%5E2%3D%28a%29%5E2%5D)
Using the formula 
, we get
Therefore, the required equation after completing the square is .
