1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
fredd [130]
3 years ago
12

PLEASE HELP!!!

Mathematics
1 answer:
4vir4ik [10]3 years ago
7 0

v=πr^2(r+7) in my opinion is the correct expression

You might be interested in
A certain college graduate borrows 7864 dollars to buy a car. The lender charges interest at an annual rate of 13%. Assuming tha
White raven [17]

Answer:

Therefore rate of payment = $ 3145.72

Therefore the rate of interest = =$1573.17

Step-by-step explanation:

Consider A represent the balance at time t.

A(0)=$ 7864.

r=13 % =0.13

Rate payment = $k

The balance rate increases by interest (product of interest rate and current balance) and payment rate.

\frac{dB}{dt} = rB-k

\Rightarrow \frac{dB}{dt} - rB=-k.......(1)

To solve the equation ,we have to find out the integrating factor.

Here p(t)= the coefficient of B =-r

The integrating factor =e^{\int p(t) dt

                                     =e^{\int (-r)dt

                                     =e^{-rt}

Multiplying the integrating factor the both sides of equation (1)

e^{-rt}\frac{dB}{dt} -e^{-rt}rB=-ke^{-rt}

\Rightarrow  e^{-rt}dB - e^{-rt}rBdt=-ke^{-rt}dt

Integrating both sides

\Rightarrow \int e^{-rt}dB -\int e^{-rt}rBdt=\int-ke^{-rt}dt

\Rightarrow e^{-rt}B=\frac{-ke^{-rt}}{-r} +C        [ where C arbitrary constant]

\Rightarrow B(t)=\frac{k}{r} +Ce^{rt}

Initial condition B=7864 when t =0

\therefore 7864= \frac{k}{r} - Ce^0

\Rightarrow  C= \frac{k}{r} -7864

Then the general solution is

B(t)=\frac{k}{r}-( \frac{k}{r}-7864)e^{rt}

To determine the payment rate, we have to put the value of B(3), r and t in the general solution.

Here B(3)=0, r=0.13 and t=3

B(3)=0=\frac{k}{0.13}-( \frac{k}{0.13}-7864)e^{0.13\times 3}

\Rightarrow- 0.48\frac{k}{0.13} +11614.98=0

⇒k≈3145.72

Therefore rate of payment = $ 3145.72

Therefore the rate of interest = ${(3145.72×3)-7864}

                                                 =$1573.17

4 0
3 years ago
Julio says, "If you subtract 19 from my number and multiply the difference by - 7, the result is - 28." What is Julio's number?
ra1l [238]

Answer:

23

Step-by-step explanation:

Basically I did it backwards & opposites:

-28 divided by -7 = 4

4 + 19 = 23

I checked btw and it worked.

4 0
2 years ago
Given (0,1) and (2, 4). The slope between the two points is ...The equation of the line through the two points is
liubo4ka [24]

Answer:

3/2

Step-by-step explanation:

because the equations y 2 - y 1 over x 2 - x 1 is 4-1 over 2-0 and that is 3/2

3 0
3 years ago
4. A mountain climber needs to descend 2,000 feet.
DENIUS [597]

Answer:

C. 500 ft

Step-by-step explanation:

If we want to make it all equal, we can divide the 2,000 ft by 4 because we have 4 equal descents.

2000 ÷ 4 = 500

He should travel <u>500 feet</u> in each descent.

8 0
3 years ago
Some help please♥️♥️♥️♥️
melamori03 [73]

Answer:

-5

Step-by-step explanation:

4 0
3 years ago
Other questions:
  • Select ALL the correct answers. Select all the expressions that are equivalent to the polynomial below. (4x+5)(-3x-1)
    9·1 answer
  • Let ff be the function that assigns to each student in the class her biological mother.
    8·1 answer
  • What is the solution set of the following equation? -5x x 9 = -4x 12
    8·1 answer
  • Did the greeks use erasers in geometric construction?
    7·2 answers
  • In triangle ABC, ∠A and ∠B are complementary, where cos A = 0.24. What is the measure, to the nearest degree of, ∠B?
    14·1 answer
  • What is the value of the expression |-7|+|-4|
    7·2 answers
  • Slope equation of (3,-4)
    11·1 answer
  • Find the slope, if it exists of the line containing the points (-4, 0) and (-5,-3)
    5·2 answers
  • HELPPP pweaseeee :( im confused again
    15·1 answer
  • Need help with the slope​
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!