What is the answer to this equation

A and B can fill a cistern in 4 hours. A and C can fill

kirill [66]

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

4 0

3 years ago

The wolfpack has one 11 games and lost 9 games this season. what percent of its games did the wolfpack win?

Murrr4er [49]

In fractions they had won 11/20 games. Then if you convert the fraction to a percent you would get 55% after multipling by 5/5 to get the denominator of 100.

The answer would be 55%.

4 0

3 years ago

Exampes of where we use perimeter in our everyday lives

RideAnS [48]

Calculate a rooms edge

7 0

3 years ago

Read 2 more answers

A fraction becomes 4÷5 if 1 is added to both numerator and denominator. If, however, 5 is subtracted from both numerator and den

tia_tia [17]

Answer:

$\dfrac{7}{9}$

Step-by-step explanation:

$\dfrac{x+1}{y+1}=\dfrac{4}{5}\\\Rightarrow 5x-4y=-1$

$\dfrac{x-5}{y-5}=\dfrac{1}{2}\\\Rightarrow 2x-y=5$

Putting it in matrix form

$\begin{bmatrix}a_{1}&b_{1}\\a_{2}&b_{2}\end{bmatrix}{\begin{bmatrix}x\\y\end{bmatrix}=\begin{bmatrix}{c_{1}}\\{c_{2}}\end{bmatrix}\\\Rightarrow\begin{bmatrix}5 & -4\\2 & -1\end{bmatrix}\begin{bmatrix}x\\ y\end{bmatrix}=\begin{bmatrix}-1\\ 5\end{bmatrix}$

From Cramer's rule we have

$x=\dfrac{\begin{vmatrix}c_1 &b_1 \\ c_2 & b_2\end{vmatrix}}{\begin{vmatrix}a_1 &b_1 \\ a_2& b_2\end{vmatrix}}\\\Rightarrow x=\dfrac{\begin{vmatrix}-1 &-4 \\ 5 & -1\end{vmatrix}}{\begin{vmatrix}5 &-4 \\ 2& -1\end{vmatrix}}\\\Rightarrow x=\dfrac{1+20}{-5+8}\\\Rightarrow x=7$

$y=\dfrac{\begin{vmatrix}a_1 &c_1 \\ a_2 & c_1\end{vmatrix}}{\begin{vmatrix}a_1 &b_1 \\ a_2& b_2\end{vmatrix}}\\\Rightarrow y=\dfrac{\begin{vmatrix}5 &-1 \\ 2 & 5\end{vmatrix}}{\begin{vmatrix}5 &-4 \\ 2& -1 \end{vmatrix}}\\\Rightarrow y=\dfrac{25+2}{-5+8}\\\Rightarrow y=9$

Verifying the results

$\dfrac{7+1}{9+1}=\dfrac{8}{10}=\dfrac{4}{5}$

$\dfrac{7-5}{9-5}=\dfrac{2}{4}=\dfrac{1}{2}$

Hence, the fraction is $\dfrac{7}{9}$ .

6 0

3 years ago

Help me please !!!!!!

stira [4]

Yes, the relationship is proportional. 3 * 3.2 = 9.6. And 5 * 3.2 = 16.

3 0

3 years ago