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3 years ago

11

PLEASE PLEASE PLEASE HELP ME I WILL MARK BRAINLIEST!!!!

2 answers:

docker41 [41]3 years ago

8 0

Answer:

(A)

Step-by-step explanation:

The large central vacuole is surrounded by its own membrane and contains water and dissolved substances. Its primary role is to maintain pressure against the inside of the cell wall

ahrayia [7]3 years ago

3 0

C it should be c I think

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4 divided by 2/9? If you could, please also explain.

shtirl [24]

You do 4/1 divided by 2/9

4 2
_ divided by _

1 9

Equals 18

(You have to multiply by the reciprocal)

4/1 times 1/4
And
2/9 times 1/4

Hope I helped!!!

7 0

3 years ago

Which statements are true? Check all that apply. TIMED! WILL GIVE BRAINLIEST!

gladu [14]

Answer:

The 1st, 3rd, 4th, 5th are correct

7 0

3 years ago

The Department of Agriculture is monitoring the spread of mice by placing 100 mice at the start of the project. The population,

uranmaximum [27]

Answer:

Step-by-step explanation:

Assuming that the differential equation is

$\frac{dP}{dt} = 0.04P\left(1-\frac{P}{500}\right)$ .

We need to solve it and obtain an expression for $P(t)$ in order to complete the exercise.

First of all, this is an example of the logistic equation, which has the general form

$\frac{dP}{dt} = kP\left(1-\frac{P}{K}\right)$ .

In order to make the calculation easier we are going to solve the general equation, and later substitute the values of the constants, notice that $k=0.04$ and $K=500$ and the initial condition $P(0)=100$ .

Notice that this equation is separable, then

$\frac{dP}{P(1-P/K)} = kdt$ .

Now, intagrating in both sides of the equation

$\int\frac{dP}{P(1-P/K)} = \int kdt = kt +C$ .

In order to calculate the integral in the left hand side we make a partial fraction decomposition:

$\frac{1}{P(1-P/K)} = \frac{1}{P} - \frac{1}{K-P}$ .

So,

$\int\frac{dP}{P(1-P/K)} = \ln|P| - \ln|K-P| = \ln\left| \frac{P}{K-P} \right| = -\ln\left| \frac{K-P}{P} \right|$ .

We have obtained that:

$-\ln\left| \frac{K-P}{P}\right| = kt +C$

which is equivalent to

$\ln\left| \frac{K-P}{P}\right|= -kt -C$

Taking exponentials in both hands:

$\left| \frac{K-P}{P}\right| = e^{-kt -C}$

Hence,

$\frac{K-P(t)}{P(t)} = Ae^{-kt}$ .

The next step is to substitute the given values in the statement of the problem:

$\frac{500-P(t)}{P(t)} = Ae^{-0.04t}$ .

We calculate the value of $A$ using the initial condition $P(0)=100$ , substituting $t=0$ :

$\frac{500-100}{100} = A}$ and $A=4$ .

So,

$\frac{500-P(t)}{P(t)} = 4e^{-0.04t}$ .

Finally, as we want the value of $t$ such that $P(t)=200$ , we substitute this last value into the above equation. Thus,

$\frac{500-200}{200} = 4e^{-0.04t}$ .

This is equivalent to $\frac{3}{8} = e^{-0.04t}$ . Taking logarithms we get $\ln\frac{3}{8} = -0.04t$ . Then,

$t = \frac{\ln\frac{3}{8}}{-0.04} \approx 24.520731325$ .

So, the population of rats will be 200 after 25 months.

6 0

3 years ago

Joel earns a commission of 5% on the audio equipment he sells , and the store keeps the rest . He sells a $750 amplifier. A. How

den301095 [7]

Answer:

Joel earns $35.00 commission and the store keeps $715.

Step-by-step explanation:

You need to figure 5% of what he sold - or 5% of $750.

Of course, you can use a calculator, or multiply $750 by .05. I prefer to think of 10 percent ($75.00) and half that to get 5%. $35.00.

Joel earns $35.00 on the sale. Not bad!

If he gets to keep $35, deduct this from the price to find out how much the store will keep.

$750 - $35 - $715.

5 0

3 years ago

Read 2 more answers

You are looking toronto corto go to Macon and back (210 mites)

nydimaria [60]

B would be ur answer :)) told

7 0

2 years ago