Help me please guys

Answer:

B) 67°C.

Step-by-step explanation:

Newton's Law of Cooling is given by:

[tex]\displaystyle \frac{dT}{dt}=k(T-A)[/tex]

Where T is the temperature of the coffee, A is the room temperature, and k is a positive constant.

We are given that the coffee cools from 100°C to 90°C in one minute at a room temperature A of 25°C.

And we want to find the temperature of the coffee after four minutes.

First, solve the differential equation. Multiply both sides by dt and divide both sides by (T - A). Hence:

[tex]\displaystyle \frac{dT}{T-A}=k\, dt[/tex]

Take the integral of both sides:

[tex]\displaystyle \int \frac{dT}{T-A}=\int k\, dt[/tex]

Integrate:

[tex]\displaystyle \ln\left|T-A\right| = kt+C[/tex]

Raise both sides to e:

[tex]|T-A|=e^{kt+C}=Ce^{kt}[/tex]

The temperature of the coffee T will always be greater than or equal to the room temperature A. Thus, we can remove the absolute value:

[tex]\displaystyle T=Ce^{kt}+A[/tex]

We are given that A = 25. Hence:

[tex]\displaystyle T=Ce^{kt}+25[/tex]

Since the coffee cools from 100°C to 90°C, the initial temperature of the coffee was 100°C. Thus, when t = 0,T = 100:

[tex]100=Ce^{k(0)}+25\Rightarrow C=75[/tex]

Hence:

[tex]T=75e^{kt}+25[/tex]

We are given that the coffee cools from 100°C to 90°C after one minute at a room temperature of 25°C.

So, T = 90 given that t = 1. Substitute:

[tex]90=75e^{k(1)}+25[/tex]

Solve for k:

[tex]\displaystyle e^k=\frac{13}{15}\Rightarrow k=\ln\left(\frac{13}{15}\right)[/tex]

Therefore:

[tex]\displaystyle T=75e^{\ln({}^{13}\! /\!{}_{15})t}+25[/tex]

Then after four minutes, the temperature of the coffee will be:

[tex]\displaystyle \begin{aligned} \displaystyle T&=75e^{\ln({}^{13}\! /\!{}_{15})(4)}+25\\\\&\approx 67^\circ\text{C}\end{aligned}[/tex]

Hence, our answer is B.

Answer:

B=-5

Step-by-step explanation:

Slope=rise/run

The line passes in

P1(-1,3)

and

P2(0,-2)

So slope=(3-(-2))/(-1-0)=5/-1=-5

Answer:

c) x=126

Step-by-step explanation:

tell me if I get it right

Answer:

21-3=18

Hope This Helps!!!

Answer:

18

Step-by-step explanation:

7(3)= 21

15/5=3

21-3=18

Answer:

11.26 m

Step-by-step explanation:

The height of the tree is about 11.25 meters.

When the respective sides are proportional and the corresponding angles are congruent, two triangles are said to be similar.

Given that, the height of the person is 1.55 meters, the length of the tree's shadow is 38.15 meters, and the distance between the person and the tree is 32.9 meters.

Let the height of the tree be x.

Note that the scenario makes two similar triangles.

Since the ratio of the side lengths of similar triangles is proportional, it follows:

(38.15 - 32.9)/1.55 = 38.15/x

5.25/1.55 = 38.15/x

3.39 = 38.15/x

x = 38.15/3.39

x = 11.25

Hence, the height of the tree is about 11.25 meters.

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Answer:

I think that second option represents the function of f(x) = 4x² - 4x -8/2x+2.

Answer:

Please include the statements too

Answer:

$121

Step-by-step explanation:

Find how much additional money it will cost from the attendees:

39(3)

= 117

Add the other $4:

117 + 4

= 121

So, it will cost $121

Answer:

40

Step-by-step explanation:

A+B+C = 31

Add 3 years to each age

A+3  +B+3  + C+3  = 31 +3+3+3

They will be

A+3  +B+3  + C+3  = 40

Answer:

it will be 40

Step-by-step explanation:

If they are altogether 31 years old now in 3 years we just add 9 thus it is 40

Answer: C. (−4, 0), (2, 0)

Step-by-step explanation:

By solution, I believe it means the roots of the equation(aka zeros), meaning the points where the graph intersects the x-axis(aka x-intercepts). It intersects at two points: (−4, 0) and (2, 0)

Answer:

Step-by-step explanation:

I got it right on my 8.06 exam! ✨ Keep believing, superstar!

and go see Sing 2 for me..its an awesome movie and it'll make u smile!

Answer: C= 1,090 and the W= 5.

Answer:

1. Cong SSS 2.Cong SSS 3.Not Cong 4.Not Cong 5.Cong SAS 6.Cong SSS 7.Cong SAS 8.Cong SSS 9.Cong SSS 10.Cong SAS 11.d 12.a 13.a 14.b 15.a

Step-by-step explanation:

Explanation:

The phrasing "given that he or she is a graduate" means we focus on the middle row only. We ignore everything else.

We see that A = 1879 graduates receive financial aid out of B = 2610 graduates total.

This means the probability we want is therefore A/B = 1879/2610 = 0.7199 approximately. This converts to 71.99% and that rounds to 72%

Step-by-step explanation:

solve for what ?? do you mean graph the function??

Answer:

Step-by-step explanation:

∠1 = 38    {Vertically opposite angles}

∠2 = 39 + 36 = 75

Exterior angle equals the sum of opposite interior angles.

x = ∠1 +∠2        

 = 38 + 75

x = 113

Answer:

B and C

Step-by-step explanation:

Decimals are well aligned when performing arithmetic operations if the equations are arranged in such a way that the decimal points are exactly vertically arranged, each following each other. This will ensure the right answer is gotten. Each place value is placed on the same vertical line on each other.

The equation in option B is correctly aligned. Because the decimal points are in the same vertical line and also the equation in option C.

Answer

15. 12/25

Step-by-step explanation:

Because the surface value of this question

Answer:

Luis’s, because he flipped the inequality sign when he subtracted

Step-by-step explanation:

7.2b + 6.5 > 4.8b – 8.1.

Amelia started by subtracting 7.2b from both sides to get

6.5 > –2.4b – 8.1

Correct

Luis started by subtracting 4.8b from both sides to get

2.4b + 6.5 < – 8.1

Incorrect

Shauna started by subtracting 6.5 from both sides to get

7.2b > 4.8b – 14.6

Correct

Clarence started by adding 8.1 to both sides to get

7.2b + 14.6 > 4.8b

Correct

Luis’s is incorrect because he flipped the inequality sign when he subtracted

Answer: Yes

Step-by-step explanation: Let's first find the missing angle in the second triangle and to find this angle, remember that the sum of the measures of a triangle is 180 degrees so you should find that our missing angle is 67°.

Now, notice that we have two angles and the included side of one triangle

congruent to two angles and the included side of a second triangle.

Therefore, we can say the triangles are congruent by ASA.

Answer:

profit=20%

Step-by-step explanation:

profit%=sp-cp/cp×100%

=1500-1250/1250×100

=250/1250×100

=20%

Answer:

The actual price of the article was Rs. 1200.

Step-by-step explanation:

mp (marked price)

ap (actual price)

[tex]mp = 1380[/tex]

[tex]mp = ap + 15\%(ap)[/tex]

[tex]1 380 = ap + \frac{15}{100} ap[/tex]

[tex]1380 = \frac{100}{100} ap + \frac{15}{100} ap[/tex]

[tex]1380 = \frac{115}{100} ap[/tex]

[tex]1380 \div \frac{115}{100} = ap[/tex]

[tex]1380 \times \frac{100}{115} = ap[/tex]

[tex] \frac{138000}{115} = ap[/tex]

[tex]1200 = ap[/tex]

The actual price of the article is given by the equation A = $ 1,200

What is an Equation?

Equations are mathematical statements with two algebraic expressions flanking the equals (=) sign on either side.

It demonstrates the equality of the relationship between the expressions printed on the left and right sides.

Coefficients, variables, operators, constants, terms, expressions, and the equal to sign are some of the components of an equation. The "=" sign and terms on both sides must always be present when writing an equation.

Given data ,

Let the actual price of the article be A

Now , the equation will be

The marked price of the article be = $ 1380

The percentage of increase from the actual price = 15 %

So , the equation is

The actual price + percentage of increase from the actual price = 1380

Substituting the values in the equation , we get

A + ( 15/100 )A = 1380   be equation (1)

( 115/100 ) A = 1380

Multiply by 100 on both sides of the equation , we get

115A = 138000

Divide by 115 on both sides of the equation , we get

A = $ 1200

Therefore , the value of A is $ 1200

Hence , the actual price of the article is $ 1200

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Answer:

x= -5 + 5[tex]\sqrt{97}[/tex], x= -5 - 5[tex]\sqrt{97}[/tex]

Step-by-step explanation:

Since this quadratic is set to zero, we can use the quadratic formula to solve this.

x^2 + 10x - 2400 = 0​

Quadractic formula =  x= -b +- [tex]\sqrt{b^2 - 4ac}[/tex] /2a

For this equation:

a= 1, b=10, c=-2400

Plug these numbers into the equation and solve.

x= -10 +- [tex]\sqrt{10^2 - 4(1)(-2400}[/tex])/2(1)

x= -10 +- [tex]\sqrt{100 + 9,600}[/tex]/2

x= -10 +- [tex]\sqrt{9,700}[/tex]/2

x= -10 +- [tex]\sqrt{2^2 * 5^2 * 97}[/tex]/2

x= -10 +- 5 * 2[tex]\sqrt{97}[/tex]/2

x= -10 +- 10[tex]\sqrt{97}[/tex] / 2

Divide by 2.

x= -5 +- 5[tex]\sqrt{97}[/tex]

Answer:

x= -5 + 5[tex]\sqrt{97}[/tex] or x= -5 - 5[tex]\sqrt{97}[/tex]

Answer:

-5.5+2=x should be equal to 3.5 on the number line and as for the other question it is D) It is a decimal that terminates after three decimal places

Step-by-step explanation:

When graphing -5.5+2=x it equals to 3.5 on the Domain and the other question you just divide the numerator to its denominator equaling you with 0.875

Answer:

b must be because the therom is aas so

Answer:

B is answer

Step-by-step explanation:

just did it

Answer:

10

Step-by-step explanation:

10 percentage for this question answer

for the columns where is less than or equal zero, use the first line of the function to calculate the value of f(x)

[tex] { ( \frac{1}{3} ) }^{ - 2} - 1 = 9 - 1 = 8 \\ { ( \frac{1}{3} ) }^{ - 1} - 1 = 3 - 1 = 2 \\ { ( \frac{1}{3} ) }^{ 0} - 1 = 1 - 1 = 0[/tex]

for every x greater than zero, use the second line to determine the value

[tex] {3}^{1} - 2 = 3 - 2 = 1 \\ {3}^{2} - 2 = 9 - 2 = 7[/tex]

hope this helps and gives some insight what to do.

if there are open questions left, feel free to ask them in the comments

have a beautiful day

-Alex

We are required to find the distance between both chords.

Answer:

17 cm

Step-by-step explanation:

The two chords are parallel to each other.

This means that a perpendicular line drawn from the centre of the circle will divide both of them into 2 equal sides.

This is depicted in the image attached.

From the Image,the diagonal drawn from one end of either chord through the centre will form the hypotenuse side of either chords.

Thus, using pythagoras theorem, we have for the chord that has a length of 10 cm. Perpendicular distance from centre of chord to centre of circle is;

d = √(13² - 5²)

d = √144

d = 12

Similarly, for chord with length = 24 cm, we have;

d' = √(13² - 12²)

d' = √25

d' = 5

Therefore, distance between chords = d + d' = 12 + 5 = 17 cm

Step-by-step explanation:

Answer:

{\color{#c92786}{6-4y}}=8

6−4y=8

−4+6=8

{\color{#c92786}{-4y+6}}=8

−4y+6=82

Subtract from both sides of the equation

=

−

1

2

Answer:

0.64 feet or 7.68 inches of snow on average over the 5 days.

Step-by-step explanation:

3.2/5

0.64ft

7.68in.

Your answer is 2.98004491789381.