Write an expression that can be used to find 4x275 using mental math and properties of numbers

A wildlife biologist determines that there are approximately 200 deer in a region of a national park. The population grows at a

Amanda [17]

Answer:

FV= 200*(1.07^n)

Step-by-step explanation:

Current population= 200 deer

Growth rate= 7% per year

To calculate the future value of deer in any given years, we need to use the following formula:

FV= PV*(1+g)^n

FV= future value

PV= present value

g= growth rate

n= number of years

FV= 200*(1.07^n)

For example, the population in 5 years:

FV= 200*(1.07^5)

FV= 281

7 0

3 years ago

a direction say to use 2 tablespoons of ground coffee for every 6 ounces of water. How much coffee should you use for 33 ounces

Sever21 [200]

Five and a half tablespoons

3 0

3 years ago

Read 2 more answers

Determine the values of the constants r and s such that i(x, y) = x rys is an integrating factor for the given differential equa

garri49 [273]

$\underbrace{y(7xy^2+6)}_{M(x,y)}\,\mathrm dx+\underbrace{x(xy^2-1)}_{N(x,y)}\,\mathrm dy=0$

For the ODE to be exact, we require that $M_y=N_x$ , which we'll verify is not the case here.

$M_y=21xy^2+6$
$N_x=2xy^2-1$

So we distribute an integrating factor $i(x,y)$ across both sides of the ODE to get

$iM\,\mathrm dx+iN\,\mathrm dy=0$

Now for the ODE to be exact, we require $(iM)_y=(iN)_x$ , which in turn means

$i_yM+iM_y=i_xN+iN_x\implies i(M_y-N_x)=i_xN-i_yM$

Suppose $i(x,y)=x^ry^s$ . Then substituting everything into the PDE above, we have

$x^ry^s(19xy^2+7)=rx^{r-1}y^s(x^2y^2-x)-sx^ry^{s-1}(7xy^3+6y)$
$19x^{r+1}y^{s+2}+7x^ry^s=rx^{r+1}y^{s+2}-rx^ry^s-7sx^{r+1}y^{s+2}-6sx^ry^s$
$19x^{r+1}y^{s+2}+7x^ry^s=(r-7s)x^{r+1}y^{s+2}-(r+6s)x^ry^s$
$\implies\begin{cases}r-7s=19\\r+6s=-7\end{cases}\implies r=5,s=-2$

so that our integrating factor is $i(x,y)=x^5y^{-2}$ . Our ODE is now

$(7x^6y+6x^5y^{-1})\,\mathrm dx+(x^7-x^6y^{-2})\,\mathrm dy=0$

Renaming $M(x,y)$ and $N(x,y)$ to our current coefficients, we end up with partial derivatives

$M_y=7x^6-6x^5y^{-2}$
$N_x=7x^6-6x^5y^{-2}$

as desired, so our new ODE is indeed exact.

Next, we're looking for a solution of the form $\Psi(x,y)=C$ . By the chain rule, we have

$\Psi_x=7x^6y+6x^5y^{-1}\implies\Psi=x^7y+x^6y^{-1}+f(y)$

Differentiating with respect to $y$ yields

$\Psi_y=x^7-x^6y^{-2}=x^7-x^6y^{-2}+\dfrac{\mathrm df}{\mathrm dy}$
$\implies\dfrac{\mathrm df}{\mathrm dy}=0\implies f(y)=C$

Thus the solution to the ODE is

$\Psi(x,y)=x^7y+x^6y^{-1}=C$

4 0

3 years ago

Please help quick I also give brainliest <3 also please out the units

Ira Lisetskai [31]

Answer:

1. 20.4

2. 84

3. 56

4. 171

5. 132

6. 297

7. 100

8. 56

9. 51

10. 828

Bonus: 644

Step-by-step explanation:

Sorry, if some are wrong.

7 0

3 years ago

Solve For x and Solve For y:

Slav-nsk [51]

Answer: y= 16.97 ×=7.27

Step-by-step explanation:

Click on file for workings

5 0

2 years ago