Answer:
8:20
Step-by-step explanation:
What does the speaker do well here? Check all that apply. asks questions prepares thoroughly includes information and opinions responds to questions speaks mostly about her opinions
Answer: B C D
Step-by-step explanation:
A population of beetles are growing according to a linear growth model. The initial population (week 0) is P0=9, and the population after 7 weeks is P7=37.
Find an explicit formula for the beetle population after n weeks.
After how many weeks will the beetle population reach 93?
Answer:
y = 4x + 9
week 21
Step-by-step explanation:
first I did 37-9 and got 28 I divide that by 7 ( seven weeks) and got 4 so I know the slope is 4.
so to find how many weeks till 93 I did; 93 = 4x + 9. We have to get x by its self so I minus 9 by both sides and got 84 = 4x. So now we divid both sides by 4 to get x by its self and we end up with 21 = x
The concentration of dichlorodiphenyltrichloroethane (DDT - an infamous pesticide) in Lake Michigan has been declining exponentially over many years. In 1971, the DDT concentration was 13.00 ppm (parts per million). In 1984, the DDT concentration was 2.22 ppm.
Using these data points, determine the exponential decay function to model the DDT concentration decline in terms of years, tt, where t=0t=0 represents the year 1971.
A) Write your function as y = Ce^{rt}y=Ce^rt. Round your value of rr to four decimal places.
B) Another way to write the function down is known as the half-life formula, written as y = C(0.5)^{t/H}y=C(0.5)^t/H, where HH is the time required for the concentration to get cut in half. Using the initial two data points, find the value of HH, rounded to 2 decimal places. Show all Algebraic work.
C) The goal was to reduce the DDT concentration to 0.98 ppm by 1995. Was this possible according to your model?
Answer: A) [tex]y=13e^{-0.1359t}[/tex]
B) H = 5.10
C) Yes
Step-by-step explanation: Exponential Decay function is a model that describes the reducing of an amount by a constant rate over time. Generally, it is written in the form: [tex]y(t)=Ce^{rt}[/tex]
A) C is initial quantity, in this case, the initial concentration of DDT. To determine r, using the data given:
[tex]y(t)=Ce^{rt}[/tex]
[tex]2.22=13e^{13r}[/tex]
[tex]e^{13r}=0.1708[/tex]
Using a natural logarithm property called power rule:
[tex]13r=ln(0.1708)[/tex]
[tex]r=\frac{ln(0.1708)}{13}[/tex]
[tex]r=-0.1359[/tex]
The decay function for concentration of DDT through the years is [tex]y(t)=13e^{-0.1359t}[/tex]
B) The value of H is calculated by [tex]y=C(0.5)^{\frac{t}{H} }[/tex]
[tex]2.22=13(0.5)^{\frac{13}{H} }[/tex]
[tex](0.5)^{\frac{13}{H} }=0.1708[/tex]
Again, using power rule for logarithm:
[tex]\frac{13}{H} log(0.5)=log(0.1708)[/tex]
[tex]\frac{13}{H} =\frac{log(0.1708)}{log(0.5)}[/tex]
[tex]\frac{13}{H} =2.55[/tex]
H = 5.10
Constant H in the half-life formula is H=5.10
C) Using model [tex]y(t)=13e^{-0.1359t}[/tex] to determine concentration of DDT in 1995:
[tex]y(24)=13e^{-0.1359.24}[/tex]
y(24) = 0.5
By 1995, the concentration of DDT is 0.5 ppm, so using this model is possible to reduce such amount and more of DDT.
Kari weighs x pounds. Her sister, Maddie, weighs 4 pounds more than her. Their dad weighs 5 times more than Maddie. Write an expression to show the weight of the dad. Simplify the expression.
Answer:
x plus 4 times 5
Step-by-step explanation:
Answer:
5x + 20
Step-by-step explanation:
5 (x + 4)
which is 5x + 20
.
Write 23 between two consecutive multiples of 8. tell me the truth
i need help please on this math
Answer:
a
Step-by-step explanation:
Answer:
The answer is A
Step-by-step explanation:
If you put in a calculator 4/5 and then 64/80 you get the same decimal meaning that they have the same ratio.
Which Expression Is Equivalent To 4(x+3)
A. 4x+3
B. 4x+12
C. 4x+3x
D. 4 + x+3
Answer:
B
Step-by-step explanation:
Distributive property
[tex]4(x + 3)[/tex]
[tex]4 \times x + 4 \times 3[/tex]
[tex]4x + 12[/tex]
How do you do these two questions?
Answer:
T = -22/r + 39
(a) y = [130 − 130e^(-0.015t)] / 3
(b) 22.9
Step-by-step explanation:
d²T/dr² + 2/r dT/dr = 0
If S = dT/dr, then:
dS/dr + 2/r S = 0
dS/dr = -2/r S
dS / S = -2/r dr
ln S = -2 ln r + C
S = e^(-2 ln r + C)
S = Ce^(-2 ln r)
S = C [e^(ln r)]^-2
S = C / r²
dT/dr = C / r²
dT = C dr / r²
T = -C / r + D
When r=1, T=17.
17 = -C + D
When r=2, T=28.
28 = -C/2 + D
Solving:
11 = C/2
C = 22
D = 39
T = -22/r + 39
We can check our answer by finding dT/dr and d²T/dr².
dT/dr = 22/r²
d²T/dr² = -44/r³
Plug into the original equation:
d²T/dr² + 2/r dT/dr = 0
-44/r³ + 2/r (22/r²) = 0
0 = 0
The total flow into the tank is 15 L/min, and the total flow out is 15 L/min, so the volume is constant at 1000 L. The amount of salt added to the tank is:
(0.05 kg/L) (5 L/min) + (0.04 kg/L) (10 L/min) = 0.65 kg/min
If y is the amount of salt in the tank at time t, and y/1000 is the concentration in the tank at time t, then the amount of salt removed from the tank is:
(y/1000 kg/L) (15 L/min) = 0.015y kg/min
The change in salt over time equals the amount of salt in minus the amount of salt out.
dy/dt = 0.65 − 0.015y
-200 dy/dt = 3y − 130
dy / (3y − 130) = -0.005 dt
3 dy / (3y − 130) = -0.015 dt
ln(3y − 130) = -0.015t + C
3y − 130 = Ce^(-0.015t)
3y = 130 + Ce^(-0.015t)
y = [130 + Ce^(-0.015t)] / 3
At t=0, y=0:
0 = (130 + C) / 3
C = -130
y = [130 − 130e^(-0.015t)] / 3
At t=50:
y = [130 − 130e^(-0.75)] / 3
y ≈ 22.9
Determine the value of y, if x is –9.
y = |x|-7
Ax+by=c solve for y
Answer:
y = -Ax + C
Step-by-step explanation:
Ax + By = C
-ax -ax
By = -Ax + C
Answer:
y = -Ax + C
A recipe says it produces the best sweet tea. In addition to using tea bags, the recipe calls for 1/2 cup of sugar for every 1 1/2 cups of water. Write an equation that shows the relationship between the number of cups of sugar to the number of cups of water in this recipe. Let x represent the number of cups of sugar and y represent the number of cups of water
Answer:
y = 3x
Step-by-step explanation:
In this case, the ratio between sugar and water is 0.5 : 1.5 or 1 : 3.
That means that you need three cups of water for every cup of sugar.
In order to put this into an equation, the slope would be 3/1 or simply 3, and the y-intercept is 0. Even if you used the 0.5 : 1.5 ratio, the slope would be the same since 1.5 / 0.5 = 3.
2. Choose the correct answer for the following equation: *
(2x105) + (7x104) + (6x103) + (5x101)
O 27,065
O 2,765
O 27,650
O 270,650
Plssss help
Answer:
270,650 is the answer
Step-by-step explanation:
Karla grows vegetables and collected 32 1/2 lbs of produce to give to her friends. She gave her best friend 8 1/4. How much produce, in pounds, does Karla have left, PLEASE NEED HELP ASP
Answer:
24 1/4 lbs
Step-by-step explanation:
She starts off with 32 1/2 lbs.
She then gives 8 1/4 to her friend.
To find how much she has left, we subtract 8 1/4 from 32 1/2.
To make this easier, lets make them both have a common denominator:
32 2/4 - 8 1/4 = 24 1/4
I hope this helped, please mark Brainliest, thank you so much!
Write in slope intercept form M=6,B=1
Answer:
y=6x+1
Step-by-step explanation:
y=mx+b
You replace m with 6 and b with 1.
Answer:
m=6,b=1
Step-by-step explanation:
bc find the value of b using formal for the equation of the line , hope this helped ^^
yo could anyone help me with this question chance to get brainliest and please and thank you
Gabriel opened a bank account. The balance is adjusted at a constant rate each week.
This equation y = 15x + 35 can be used to represent this situation, where y is the account balance in dollars and x is the number of weeks since he opened the account.
Which statement best describes the account balance, given this equation?
Gabriel opened the account with $35 and is depositing $15 per week into his bank account.
Gabriel opened the account with $15 and is depositing $35 per week into his bank account.
Gabriel opened the account with $35 and is deducting $15 per week from his bank account.
Gabriel opened the account with $15 and is deducting $35 per week from his bank account.
Answer: B: Gabriel opened the account with $15 and is depositing $35 per week into his bank account.
The Math Counts Club had a party at their school. There were 20 cookies and 40 slices of pizza to be shared equally. Each student had the same number of whole cookies and the same number of slices of pizza with nothing left over. How many students could have been at the party? LCM or GCF?
Answer:
gcf is 20 lcm is 40
Step-by-step explanation:
• The height of a particular species of tree, in feet, r years after it is planted can be modeled by the
linear function h(x) = 5.27 +3.12x. Which of the following best interprets the y-intercept of the
linear model?
a. The average height of the species when planted is 5.27 feet.
b. The average height of the species when planted is 3.12 feet.
c. The species of tree grows by an average height of 5.27 feet per year.
d. The species of tree grows by an average height of 3.12 feet per year.
4:■ =8 :14 fhjyghjhgj
Answer:
■ = 7
Explanation:
Because there two ratios are proportional as a result of being equal.
To find the missing part of the ratio, cross multiply, and solve for ■ by converting them into their equivilent fractions.
i.e a : b = a/b.
So 4 : ■ becomes 4/■. And 8 : 14 becomes 8/14.
i.e a/b = c/d → b × c = a × d → bc = ad
Now 4/■ = 8/14 → ■ × 8 = 14 × 4 → 8■ = 56.
8■/8 = 56/8
1■ = 7
■ = 7
This method works for a missing part pretty much anywhere.
____________________
This is a little faster for ratios:
To find the value of the unknown part of the ratio,
just find the factor between two corresponding numbers, and apply that to the known number corresponding to the unknown part.
4 : ■ = 8 : 14
Notice that 4 corresponds to 8
So the factor between these is 2.
Since from 8 to 4 is a multiple of 1/2. 8 × 1/2 = 4, and 14 × 1/2 = ■.
Therefore ■ = 14 × 1/2 = 14/2 = 7
If you place 950 kg of material into a mixer and discharge 895 kg of product, what percentage of the raw materials was discharged
Answer:
94.2%
Step-by-step explanation:
Most of the materials is converted into product.
Assuming the amount of material discharged = the amount of product discharged.
The percentage of material discharged is
(895/950)×100 = 94.2%
If P is the circumcenter △ A B C, and AD =3x - 11, DB =5x - 29, PC =18, find DP.
Answer:
8.2
Step-by-step explanation:
1. Since AD is equal to DB, we will need to set 3x-11 equal to 5x-29. When you solve the equation you will get 9 for x.
2. Plug the 9 in for x in DB (you could plug it in for AD instead if you want since DB and AD are equal to each other). You should get 16.
3. Take a look at the smaller triangle DBP which is part of triangle ABC. We will need to use the Pythagorean Theorem. Square the legs of the triangle and set it equal to the hypotenuse squared. One of the legs, DP, is unknown so we will just have it as x. The other leg is DB, which is 16.
* PB is the hypotenuse and has a value of 18. Remember that P is the circumcenter, which means it is equidistant to each vertex and each angle bisector is equal to each other. As a result PC is equal to PB which happens to be 18.
You should have it something like this:
16^2 + x^2 = 18^2
Now do all the squaring and stuff and you should eventually get x^2 = 68
4. Square root x^2 = 68 and you will get a long decimal. You will need to round it to the tenths place.
5. After rounding you will finally get 8.2
The measurement of DP is 8.2 units.
What is circumcenter of a triangle?The circumcenter of a triangle is defined as the point where the perpendicular bisectors of the sides of that particular triangle intersect.
Given that, P is the circumcenter △ ABC, and AD = 3x - 11, DB =5x - 29,
PC = 18
Since, DP bisects AB, so, AB = DP
3x-11 = 5x-29
x = 9
DB = 5*9 - 29 = 16
Since, P is the circumcenter, then PB = PC = PA = 18
Using Pythagoras theorem in Δ BPD
PB² = DB² + DP²
DP² = PB² - DB²
DP² = 18² - 16²
DP² = 324 - 256
DP² = 68
DP = 8.2
Hence, The measurement of DP is 8.2 units.
For more references on circumcenter of a triangle, click;
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Find the value of n. 0.09 × n = 0.054
HELP PLEASEEEEEEEEEEEEEEEEEEE
Answer:
n=0.6
Step-by-step explanation:
We want to get n alone so we can divide each side by 0.09.
So then n= 0.054/0.09.
n=0.6
Hope this helps! If you have any questions on how I got my answer feel free to ask. Stay safe!
A robot can complete 6 tasks in 7/10 hour. Each task takes the same amount of time. a. How long does it take the robot to complete one task? b. How many tasks can the robot complete in one hour?
Answer:
7/60 hour or 7 minutes b) 8 or 8 4/7 depending if you consider a fraction of a task is yes or no
Step-by-step explanation:
What are the slopes to these ? Please answer
5. is slope of 0
6. is slope of -7
7. is slope of -2
8. is slope of -3/2
9. is slope of -1
10. is slope of 0 :)
Plssss just help me I have asked this question like 8 time plssssss help
Answer:
$1.50
Step-by-step explanation:
The constant of proportionality will be the cost for 1 ticket. This means you can find it by dividing the amount for 5 tickets.
7.5=5 tickets
divide both sides by 5
1.5= 1 ticket
one ticket costs $1.50, or the constant of proportionality
Answer:
1.50 would be your answer
Step-by-step explanation:
Ride Tickets x $1.50 = Cost
Hope this helpss!!
Find the value of log100,000
Answer:
Step-by-step explanation:
5
4. [-12 Points)
DETAILS
HARMATHAP12 12.4.006.
Cost, revenue, and profit are in dollars and x is the number of units.
If the marginal cost for producing a product is MC = 84 - 4e -0.01x, with a fixed cost of $6,200, find the total cost function.
C(x) =
Find the cost of producing 40 units to the nearest dollar)
$
Need Help?
Read it
Answer:
800
Step-by-step explanation:
Savannah got her hair done. If it costs $120 and she tips her hairdresser 18%, how much tip will her hairdresser receive
Answer:
21.6
Step-by-step explanation:
Do 0.18 (18%) times 120
Answer:
21.60
Step-by-step explanation:
18% of 120 is 21.60, so we would tip her hairdresser that much :)
6. When an asset increases in value, it is said to
appreciate
depreciate
be at market value
have valuized
Answer:
appreciate plzz mark as brainliest
can somebody please help me omg i’m so dumb
Answer:
A
Step-by-step explanation:
Calculate the area of this triangle.
14 cm
11 cmi
18 cm
Answer: 99cm^2
Step-by-step explanation:
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[tex]area = \frac{1}{2} \times (height) \times (base) \\ [/tex]
[tex]height = 11 \: \: cm[/tex]
[tex]base = 18 \: \: cm[/tex]
Thus :
[tex]area = \frac{1}{2} \times 11 \times 18 \\ [/tex]
[tex]area = \frac{18}{2} \times 11 \\ [/tex]
[tex]area = \frac{2 \times 9}{2} \times 11 \\ [/tex]
[tex]area = 9 \times 11[/tex]
[tex]area = 99 \: \: {cm}^{2} [/tex]
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