Suppose you add x liters of pure water to the 10 L of 25% acid solution. The new solution's volume is x + 10 L. Each L of pure water contributes no acid, while the starting solution contains 2.5 L of acid. So in the new solution, you end up with a concentration of (2.5 L)/(x + 10 L), and you want this concentration to be 10%. So we have

and so you would need to add 15 L of pure water to get the desired concentration of acid.
Answer:
F) y=3x+13
Step-by-step explanation:
y-y1=m(x-x1)
y-(-2)=3(x-(-5))
y+2=3(x+5)
y=3x+15-2
y=3x+13
The system of equations when been placed in a matrix yields
![\left[\begin{array}{ccc}650&-1\\120&1\end{array}\right]\left[\begin{array}{ccc}x\\y\end{array}\right] =\left[\begin{array}{ccc}-175\\25080\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D650%26-1%5C%5C120%261%5Cend%7Barray%7D%5Cright%5D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-175%5C%5C25080%5Cend%7Barray%7D%5Cright%5D)
<h3>What is an
equation?</h3>
An equation is an expression that shows the relationship between two or more variables and numbers.
Given the equation:
y = 650x + 175 and;
y = 25080 - 120x
Rearranging the equations gives:
650x - y = -175 and;
120x + y = 25080
Placing the equations in a matrix gives:
![\left[\begin{array}{ccc}650&-1\\120&1\end{array}\right]\left[\begin{array}{ccc}x\\y\end{array}\right] =\left[\begin{array}{ccc}-175\\25080\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D650%26-1%5C%5C120%261%5Cend%7Barray%7D%5Cright%5D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-175%5C%5C25080%5Cend%7Barray%7D%5Cright%5D)
The system of equations when been placed in a matrix yields
![\left[\begin{array}{ccc}650&-1\\120&1\end{array}\right]\left[\begin{array}{ccc}x\\y\end{array}\right] =\left[\begin{array}{ccc}-175\\25080\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D650%26-1%5C%5C120%261%5Cend%7Barray%7D%5Cright%5D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-175%5C%5C25080%5Cend%7Barray%7D%5Cright%5D)
Find out more on equation at: brainly.com/question/2972832
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(a) Take the Laplace transform of both sides:


where the transform of
comes from
![L[ty'(t)]=-(L[y'(t)])'=-(sY(s)-y(0))'=-Y(s)-sY'(s)](https://tex.z-dn.net/?f=L%5Bty%27%28t%29%5D%3D-%28L%5By%27%28t%29%5D%29%27%3D-%28sY%28s%29-y%280%29%29%27%3D-Y%28s%29-sY%27%28s%29)
This yields the linear ODE,

Divides both sides by
:

Find the integrating factor:

Multiply both sides of the ODE by
:

The left side condenses into the derivative of a product:

Integrate both sides and solve for
:


(b) Taking the inverse transform of both sides gives
![y(t)=\dfrac{7t^2}2+C\,L^{-1}\left[\dfrac{e^{s^2}}{s^3}\right]](https://tex.z-dn.net/?f=y%28t%29%3D%5Cdfrac%7B7t%5E2%7D2%2BC%5C%2CL%5E%7B-1%7D%5Cleft%5B%5Cdfrac%7Be%5E%7Bs%5E2%7D%7D%7Bs%5E3%7D%5Cright%5D)
I don't know whether the remaining inverse transform can be resolved, but using the principle of superposition, we know that
is one solution to the original ODE.

Substitute these into the ODE to see everything checks out:

Answer: 23
Step-by-step explanation:
2x + 14 = 60
2x = 46
x = 23