4.5 and maybe 16-64. If they count -
Answer:
f(9) = 35
Step-by-step explanation:
To solve this, you can take 9 and replace both x's with it and then complete the equation;
f(x) = 4x - 1
f(9) = 4(9) - 1
f(9) = 36 - 1
f(9) = 35
Hope this helps!
Answer:
24% saline
Step-by-step explanation:
Find how much saline is in both solutions:
7(0.27)
= 1.89
3(0.17)
= 0.51
Add this together:
1.89 + 0.51
= 2.4
Since there are 10 quarts in total, the concentration of the mixture can be found by dividing 2.4 by 10:
2.4/10
= 0.24
So, the concentration of the mixture is 24% saline
(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:
