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.
Help needed ! Asap rocky! U hurddd mamahuevo
Answer:
Step-by-step explanation:
Hello!
x < -45/15
=>
{xIx<-3}
(5.9)(1.102)
What’s does that mean
Answer:
brackets stand for multiplication therefore this means multiply 5.9 by 1.102..
I hope this helps and sorry if it's wrong
Did I do this right? I really don’t want to fail lol
Answer:
i think yes!!!
Step-by-step explanation:
Answer:
Yes
Step-by-step explanation:
Yes, you did this correctly.
By subtracting the volume of the cylinder from the volume of the rectangular solid, you accurately acquired the volume of the remaining figure.
And yes, your calculations are correct.
Can someone please help me
Answer:
c
Step-by-step explanation:
come on ! you can literally see that in the chart.
how many parts of the gray 3/8 are covered by the gray 1/4 ?
2 parts = 2/8 are clearly covered by 1/4.
2/8 is what part of 3/8 ?
it is the same question as "2 is what part of 3" ?
is 2 a quarter (1/4) of 3 ? no, 1/4×3 = 3/4 and not 2.
is 2 one third (1/3) of 3 ? no, 1/3 of 3 = 1/3×3 = 1 and not 2.
is 2 two thirds (2/3) of 3 ? ah, 2/3 × 3 = 2. that is correct !
is 2 three quarters (3/4) of 3 ? no, 3/4×3 = 9/4 and not 2.
once you have the same denominator, you can easily compare the numerators and ignore the denominators for such problems.
is 10 X -3+ 2X -5 and four (3X -2) equivalent?
Answer:
Yes, both equations are equivalent
Step-by-step explanation:
Simplifying [tex]10x - 3 + 2x - 5[/tex] by combining "like terms" gives us [tex]12x-8[/tex].
Now, to solve "four (3X - 2)", we need to use the distributive property. Doing [tex](4\cdot3x)-(4\cdot2)[/tex] gives us [tex]12x-8[/tex] again.
Therefore, [tex]10x - 3 + 2x - 5[/tex] and four (3X -2) are equivalent!
(Hope this helped you! If any part of the explanation doesn't make sense, or the answer is incorrect/not the answer you we're looking for, then please tell me and I will try to fix my answer as soon as possible)
does ax + by + c = 0 represent an equation of line, if a = b = 0?
Step-by-step explanation:
it will not represent the equation of a line since there's no slope
9514 1404 393
Answer:
no
Step-by-step explanation:
The equation becomes 0 = 0. This is a truism, valid for any variable values.
It is not the equation of a line.
tìm nghiệm của đa thức 2x² + 5x
Answer:
this is this because of PTI
Step-by-step explanation:
pto explain it to me on Monday and Friday Saturday morning
Answer:
[tex]2x^2+5x[/tex]
[tex]=2xx+5x[/tex]
[tex]=x\left(2x+5\right)[/tex]
Hope it helps u
Instructions: Find the value of the trigonometric ratio. Make sure to simplify the fraction if
needed.
Step-by-step explanation:
[tex] \sin(x) = \frac{12}{13} [/tex]
The value of the trigonometric ratio are; [tex]\sin(x) = \dfrac{\text{12}}{\text{13}}[/tex].
On which triangle can we apply trigonometric ratios?Trigonometric ratio can be defined in terms of ratios of perpendicular, bases and hypotenuse.
Trigonometric ratio are defined only in right angled triangles (triangles whose one angle is of 90 degree measure).
Trigonometric ratios for a right angled triangle are from the perspective of a particular non-right angle.
In a right angled triangle, two such angles are there which are not right angled(not of 90 degrees).
From the considered angle, the side opposite to it is called perpendicular, and the remaining side will be called base.
From that angle suppose its measure is θ,
[tex]\sin(\theta) = \dfrac{\text{Length of perpendicular}}{\text{Length of Hypotenuse}}[/tex]
[tex]\sin(x) = \dfrac{\text{12}}{\text{13}}[/tex]
Therefore, The value of the trigonometric ratio are; [tex]\sin(x) = \dfrac{\text{12}}{\text{13}}[/tex].
Learn more about trigonometric ratios here:
https://brainly.com/question/22599614
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anyone know collage level algebra 2? I need help
Evaluate the series: image Question 1 options: A) 392 B) 249 C) 420 D) 406
Answer:
The required sum is 392
Step-by-step explanation:
Given the sum as shown;
[tex]\sum \left \77} \atop {a=1}} \right. (3a^2-4)[/tex]
When n = 1
f(1) = 3(1)²-4
f(1) = 3 - 4
f(1) = - 1
When n = 2
f(2) = 3(2)²-4
f(2) = 12 - 4
f(2) = 8
When n = 3
f(3) = 3(3)²-4
f(3) = 27 - 4
f(3) = 23
When n = 4
f(4) = 3(4)²-4
f(4) = 48 - 4
f(4) = 44
When n = 5
f(5) = 3(5)²-4
f(5) = 75 - 4
f(5) = 71
When n = 6
f(6) = 3(6)²-4
f(6) = 108 - 4
f(6) = 104
When n = 7
f(7) = 3(7)²-4
f(7) = 147 - 4
f(7) = 143
Taking their sum
Sum = f(1)+f(2)+(3)+f(4)+f(5)+f(6)+f(7)
Sum = -1 + 8 + 23 + 44 + 71 + 104 + 143
Sum = 392
Hence the required sum is 392
Please help explanation if possible
Answer:
y = - [tex]\frac{3}{2}[/tex] x + 1
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
y = [tex]\frac{2}{3}[/tex] x + [tex]\frac{2}{3}[/tex] ← is in slope- intercept form
with slope m = [tex]\frac{2}{3}[/tex]
Given a line with slope m then the slope of a line perpendicular to it is
[tex]m_{perpendicular}[/tex] = - [tex]\frac{1}{m}[/tex] = - [tex]\frac{1}{\frac{2}{3} }[/tex] = - [tex]\frac{3}{2}[/tex] , then
y = - [tex]\frac{3}{2}[/tex] x + c ← is the partial equation
To find c substitute (- 2, 4) into the partial equation
4 = 3 + c ⇒ c = 4 - 3 = 1
y = - [tex]\frac{3}{2}[/tex] x + 1 ← equation of line
The computer technician charges $20 per visit plus $35 per hour. If the computer technician works for 2 hours, what will be the cost?
$75
$90
$55
Answer:
90
Step-by-step explanation:
To solve this problem we need to set up an expression
35x+20
35 is the cost per hour, and 20 dollars is the visit fee.
x is the amount of hours the CT can work
So if we plug in the amount for the number of hours from the problem we get
35(2)+20
Which becomes 70+20 which is 90.
Hope thsi helps!
The computer technician works for 2 hours will take total charges equal to $90 .
What is equation?An equation is a mathematical statement that is made up of two expressions connected by an equal sign.
For example, 3x – 5 = 16 is an equation. Solving this equation, we get the value of the variable x as x = 7
According to the question
The computer technician charges $20 per visit plus $35 per hour.
i.e
Let hours he work = x
therefore,
Total charge of computer technician in equation = 20 + 35x
Now,
As the computer technician works for 2 hours the cost will be
By using equation
Total charge of computer technician in dollars = 20 + 35x
where x = 2
so,
= 20 + 35*2
= $90
Hence, the computer technician works for 2 hours will take total charges equal to $90 .
To know more about equation here:
https://brainly.com/question/10413253
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three numbers are in the ratio 1:2:1 find the largest number if the sum of their cubes is 1000
Answer:
Given,
The ratio of the three numbers are 1:2:3 . Let the numbers are x , 2x and 3x.
According to the question,
x³+(2x)³+(3x)³=4,500
⟹x³+8x³+27x³=4,500
⟹36x³=4500
⟹x³=4,50036
⟹x³=125
⟹x=125−−−√3
⟹x=5
So the numbers are 5,5×2=10,5×3=15
Therefore, 5 is the smallest number.
https://www.quora.com/Three-numbers-are-in-the-ratio-1-2-3-and-the-sum-of-their-cubes-is-4-500-What-is-the-smallest-number
Can A KIND SOUL HELP ME OUT??? ALL THE ANSWERS I SEE ARE WRONG FOR THIS PROBLEM!!!!!!!!!!:(((
Find the measures of angles x, y and z in the figure.
please show how you got it so I can see if the answer makes sense!!!!
Answer:
x=y=z=106
Step-by-step explanation:
The upper line is a straight line, so x+74=180, x=106.
y and x are equal in measure as it's a pair of parallel lines and z=y as they are alternate interior angles
The HCF of 85 and 95
Answer:
So the greatest common factor 85 and 95 is 5.
Step-by-step explanation:
We will now calculate the prime factors of 85 and 95, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 85 and 95.
We will first find the prime factorization of 85 and 95. After we will calculate the factors of 85 and 95 and find the biggest common factor number .
Step-1: Prime Factorization of 85Prime factors of 85 are 5, 17. Prime factorization of 85 in exponential form is:
85 = 5^1 × 17^1
Step-2: Prime Factorization of 95Prime factors of 95 are 5, 19. Prime factorization of 95 in exponential form is:
95 = 5^1 × 19^1
Step-3: Factors of 85List of positive integer factors of 85 that divides 85 without a remainder.
1, 5, 17
Final Step: Biggest Common Factor NumberWe found the factors and prime factorization of 85 and 95. The biggest common factor number is the GCF number.
So the greatest common factor 85 and 95 is 5.
Please answer this
simplify too
Answer:
x^2-3x
pls mark me brainliest
Step-by-step explanation:
4x(x+2)-x(3x+5)
4x^2+8x-3x^2-5x
x^2-3x
Trash-A-Way charges $25 per month with an additional $0.25 per pound of trash that they pick up from your house. Garbage-No-More charges a flat fee of $45 per month. Write a system of equations to represent each plan. How many pounds of trash would make the two plans equal?
Answer:
look at the explanation
Step-by-step explanation:
Write an equation:
Trash a way : $25 + 0.25x
Garbage No More : $45 per month
so to make them equal we need to have enough trash in Trash A Way that it equals $45
25 + 0.25x =45
0.25x = 20
x = 80
So, you need to have 80 pounds of trash to make them equal
hope this helps!
please vote and heart!
Which constants can be multiplied by the equations so one variable will be eliminated when the systems are added together?
5x + 13y = 232
12x + 7y = 218
The first equation can be multiplied by –13 and the second equation by 7 to eliminate y.
The first equation can be multiplied by 7 and the second equation by 13 to eliminate y.
The first equation can be multiplied by –12 and the second equation by 5 to eliminate x.
The first equation can be multiplied by 5 and the second equation by 12 to eliminate x.
someone answer fast with a model: Kevin spends $11.25 on lunch every week during the school year.If there are 35.5 weeks during the school year how much dies Kevin spend on lunch over the entire school year? Remember to round to the nearest penny
Answer:
$399.45
Step-by-step explanation:
all you gotta do is
11.25×35.5
Which choices are equivalent to the expression below? 3sqrt5 + 8sqrt5
A. 24 start 5
B. 24 sqrt 10
C. 11 sqrt 10
D. 11 sqrt 5
Answer:
B. 24 sqrt 10
Step-by-step explanation:
Hope this helped.
Answer:
11√5
Step-by-step explanation:
just putting the question with the symbols here so its easier to find for others
Which choice is equivalent to the expression below? 3√5+8√5
A. 24√5
B. 24√10
C. 11√10
D. 11√5
Based on the markings of the two triangles, what statement could be made about ΔABC and ΔA′B′C′? Question 1 options: A) The corresponding pairs of sides and angles of ΔABC and ΔA′B′C′ aren't congruent. B) ΔABC and ΔA′B′C′ are congruent. C) ΔABC and ΔA′B′C′ are irregular polygons. D) ΔABC and ΔA′B′C′ aBased on the markings of the two triangles, what statement could be made about ΔABC and ΔA′B′C′? Question 1 options: A) The corresponding pairs of sides and angles of ΔABC and ΔA′B′C′ aren't congruent. B) ΔABC and ΔA′B′C′ are congruent. C) ΔABC and ΔA′B′C′ are irregular polygons. D) ΔABC and ΔA′B′C′ are similar but not congruent.re similar but not congruent.
Answer:
B) ΔABC and ΔA′B′C′ are congruent.
Step-by-step explanation:
Given
See attachment for [tex]\triangle ABC[/tex] and [tex]\triangle A'B'C'[/tex]
Required
Determine the relationship between both triangles
The single line on all sides of both triangles implies that the sides of the triangles are equal
i.e.
[tex]\triangle ABC \cong \triangle A'B'C'[/tex] --- sides
Similarly, the same mark on the three angles of both triangles means that the angles of the both triangles are equal
i.e.
[tex]\triangle ABC \cong \triangle A'B'C'[/tex] --- angles
Hence, both triangles are congruent
Answer:
B) ΔABC and ΔA′B′C′ are congruent.
Step-by-step explanation:
Help anyone can help me do the question,I will mark brainlest.
Answer:
552
Step-by-step explanation:
I'm almost certain this is correct. Only one step is rounded.
Answer: 942 - 225*sqrt(3)
This is roughly equivalent to 552.29
The unit for the area is in square cm, or cm^2.
The two area values above are based on pi = 3.14, so they are approximations.
============================================================
Explanation:
The radius of the circle is r = 30 because OA = 30.
The full circle has area A = pi*r^2 = 3.14*30^2 = 2826 cm^2 approximately
However, we only want 120/360 = 1/3 of this full area to get the area of the pizza slice. So the area of the pizza slice is approximately (1/3)*2826 = 942 cm^2
This is not the final answer, but helps get us there.
What we just calculated was the approximate area of the entire figure: the yellow area plus the white triangle.
If we can find the area of the white triangle, and subtract it off, then we'll find just the area of the yellow region only.
-----------------------
The SAS (side angle side) area formula for a triangle is
Area = 0.5*p*q*sin(R)
where p,q are the sides and angle R is between those sides.
Here we have p = q = 30, which are sides OA and OB, and we have R = 120 degrees as the central angle.
So the area of triangle AOB is...
Area = 0.5*p*q*sin(R)
Area = 0.5*30*30*sin(120)
Area = 450*sqrt(3)/2
Area = 225*sqrt(3)
This value is exact.
-----------------------
The area of the yellow region is therefore
(area of full figure) - (area of triangle)
(942) - (225*sqrt(3))
942 - 225*sqrt(3)
This is approximate because we used pi = 3.14 as an approximation earlier.
You could then use your calculator to say
942 - 225*sqrt(3) = 552.288568
This rounds to 552.29
rút gọn M=[ căn x -2/x-1- căn x +2/x+2 căn x+ 1] nhân x bình-2x+1/2 với x>0 x khác 1
Answer:
Step-by-step explanation:
What's the angle sum of a polygon having 7 sides.
Answer:
900°
Step-by-step explanation:
The sum of the interior angles of a polygon is
sum = 180° (n - 2) ← n is the number of sides
Here n = 7 , then
sum = 180° × 5 = 900°
x-1/(x+1)(x-5)
In 10 words or fewer, tell what value of x will make the above rational
expression equal to zero.
Answer:
x=1
Step-by-step explanation:
x-1/(x+1)(x-5)
When the numerator is equal to zero and the denominator is not equal to zero
x-1= 0
x=1
write the equation of the graph below
Answer:
Step-by-step explanation:
This is a parabola with a vertex at h = 4 and k = 5; the graph goes through the coordinate x = 6 and y = 6. We will use those 4 values to fill in the equation:
[tex]y=a(x-h)^2+k[/tex] and this will allow us to solve for the value of a:
[tex]6=a(6-4)^2+5[/tex] and
[tex]6=a(2)^2+5[/tex] and
6 = 4a + 5 and
1 = 4a so
[tex]a=\frac{1}{4}[/tex] and the equation is
[tex]y=\frac{1}{4}(x-4)^2+5[/tex]
Brianna made cookies. She used 5/8 of a cup of flour and 1/2 of a cup of sugar. How much more flour than sugar did Brianna use?
Write your answer as a fraction or as a whole or mixed number
Answer:
She used 1/8 or 12.5% more flour than sugar
Step-by-step explanation:
flour: 5/8
sugar: 1/2 = 4/8
[tex]\frac{5}{8} - \frac{4}{8} = \frac{1} {8} = 0.125[/tex]
0.125 = 12.5%
En su cuenta bancaria, Sally tiene un saldo de -\$200.90−$200.90minus, dollar sign, 200, point, 90. Su amiga Shannon tiene un saldo bancario de -\$240.55−$240.55minus, dollar sign, 240, point, 55. ¿La cuenta bancaria de cuál amiga tiene más deuda
Answer:
Shannon
Step-by-step explanation:
Cuando se habla de lo que uno tiene, podemos usar números positivos.
Por ejemplo:
Pedro tiene 10 manzanas.
Para el caso de deudas, utilizamos números negativos, por ejemplo:
Pedro tiene -10 manzanas
Lo cual significa que Pedro debe 10 manzanas a alguien.
Entonces si le diéramos a Pedro 12 manzanas, el ahora tendría:
-10 + 12 = 2
Pedro tiene 2 manzanas, porque tuvo que entregar 10 de las 12 que le dimos para pagar su deuda.
Ahora vamos a resolver el problema:
La cuenta de Sally tiene un saldo de:
S = -$200.90
El signo negativo quiere decir que Sally tiene una deuda de $200.90
La cuenta de su amiga Shannon tiene un saldo de:
S' = -$240.55
De vuelta, el signo negativo quiere decir que Shannon tiene una deuda de $240.55
Con esto ya podemos concluir que la deuda de Shannon es mayor, por lo tanto Shannon es la que tiene más deuda.
What is the least common multiple of 46, 49, and 17?
Answer:
38318
Step-by-step explanation:
Break the numbers into prime factors
46 = 23*2
49 = 7*7
17 = 17*1
The least common multiple is
23*2*7*7*17 = 38318
If you divide $65 in the ratio 6:7, what is the smaller part?
A. $13
O B. $26
C. $30
OD. $35
Answer:
$30
Step-by-step explanation:
Let the ratios be 6x and 7x
Then 65 = 6x + 7x
65 = 13x
x = 65/13
x=5
6x = 6 x 5 = $30
7x = 7 x 5 = $35
Answer From Gauth Math
Please solve if you can!
Answer:
Step-by-step explanation:
1) 76*.67 = 50.9
73 * .33 = 24.1
75% = C
2) .3 * 71 + .3*77+ .4*98=
21.3+23.1+39.2 = 83.6
83.6 = B
3) 73.24 vs. 68.55
hw 88 22 13.2
cp 84 8.4 8.4
test 59 23.6 35.4
fe 77 19.25 11.55
tats ester
totals = 73.24 68.55
