Answer:
[tex]\mathbf{A(t) = 180 - 130e ^{-\dfrac{t}{30}}}[/tex]
Step-by-step explanation:
Given that:
A tank contains 180 liters of fluid in which 50 grams dissolved inside.
Brine containing 1 gram of salt per liter is then pumped into the tank at a rate of 6 L/min
The salt pumped out[tex]= \dfrac{6 L}{180 L} = \dfrac{1}{30}[/tex] of initial amount added salt
At (t = 0) = 50
To determine the number A (t)
[tex]\dfrac{dA}{dt}=Rate_{in} - Rate _{out}[/tex]
[tex]A' = 6 - \dfrac{1}{30}A[/tex]
[tex]A' + \dfrac{1}{30}A = 6[/tex]
Integrating factor [tex]y = e^{\int\limits pdt[/tex]
[tex]y = e^{\int\limits \dfrac{1}{30}dt}[/tex]
[tex]y = e^{\dfrac{t}{30}}[/tex]
[tex](e^{ \frac{t}{30}}A)' =4 e ^{\dfrac{t}{30}}+c[/tex]
Taking integral on the both sides;
[tex]Ae ^{\dfrac{t}{30}}= 6 * 30 e^{\dfrac{t}{30}} + c[/tex]
[tex]A = 180+ ce^ {-\dfrac{t}{30}}[/tex]
At A(t = 0) = 50
50 = 180 + C (assuming C = [tex]ce ^{-\dfrac{t}{30}}[/tex])
C = 50 - 180
C = 130
[tex]\mathbf{A(t) = 180 - 130e ^{-\dfrac{t}{30}}}[/tex]
The following crosstabulation summarizes the data for two categorical variables, x and y. The variable x can take on values low, medium, or high and the variable y can take on values yes or no.
Y
X Yes No Total
Low 20 10 30
Medium 15 35 50
High 20 5 25
Total 55 50 105
1. Compute the row percentage
2. Construct a sketch percentage of frequency bar chat with x on horozontal axis.
Answer:
Step-by-step explanation:
From the given data:
The row percentage can be determined by: taking each box in each row and by dividing it with its total on that line, after that we will multiply it by 100 to get the result of it's equivalent percentage.
Table reconstruct the table from the question ; we have:
y
x Yes No Total
Low 20 10 30
Medium 15 35 50
High 20 5 25
Total 55 50 105
For Low; the total on the row is 30 ;
so for Yes: we have 20/30 × 100 = 66.7
for No ; we have 10/30 × 100 = 33.3
For Medium ; the total on the row is 50 ;
so for Yes: we have 15/50 × 100 = 30
for No ; we have 35/50 × 100 = 70
For High ; the total on the row is 25;
so for Yes: we have 20/25 × 100 = 80
for No ; we have 5/25 × 100 = 20
y
x Yes No Total
Low 66.7 33.3 100
Medium 30 70 100
High 80 20 100
b. The construction of a sketch percentage of the frequency bar chat with x on horizontal axis is shown in the attached file below.
The equation 9(u – 2) + 1.5u = 8.25 models the total miles Michael traveled one afternoon while sledding, where u equals the number of hours walking up a hill and (u – 2) equals the number of hours sledding down the hill. Which is the value of u?
Answer:
2.5
Step-by-step explanation:
[tex]9(u-2)+1.5u=8.25 \\\\9u-18+1.5u=8.25\\\\10.5u-18=8.25\\\\10.5u=26.25\\\\u=2.5[/tex]
Hope this helps!
If 9: x= x-4, then x=
0 36
18
0 24
6
Answer:
2±√13
Step-by-step explanation:
9/x=x-4
x² -4x - 9=0
x² -4x +4- 13=0
(x -2)²=13
x-2= ±√13
x= 2±√13
Among 21- to 25-year-olds, 29% say they have driven while under the influence of alcohol. Suppose that three 21- to 25-year-olds are selected at random. a)What is the probability that all three have driven while under the influence of alcohol
Answer:
P(3) = 0.0244
P(3) = 2.44%
the probability that all three selected have driven while under the influence of alcohol is 2.44% or 0.0244
Step-by-step explanation:
Given;
The probability that they have driven while under the influence of alcohol is;
P = 29% = 0.29
the probability that all three selected have driven while under the influence of alcohol is;
P(3) = P × P × P
P(3) = 0.29 × 0.29 × 0.29
P(3) = 0.024389
P(3) = 0.0244
P(3) = 2.44%
the probability that all three selected have driven while under the influence of alcohol is 2.44% or 0.0244
A large software company gives job applicants a test of programming ability and the mean for that test has been 160 in the past. Twenty-five job applicants are randomly selected from a large university and they produce a mean score of 183 with a standard deviation of 12. Use a 0.05 level of significance to test whether the mean score for students from this university is greater than 160. use the P-value method of testing hypotheses.
Answer:
[tex]t=\frac{183-160}{\frac{12}{\sqrt{25}}}=9.58[/tex]
The degrees of freedom are given by:
[tex]df=n-1=25-1=24[/tex]
And the p value would be:
[tex]p_v =P(t_{(24)}>9.58)\approx 0[/tex]
Since the p value is very low at any significance level we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 160
Step-by-step explanation:
Information provided
[tex]\bar X=183[/tex] represent the sample mean
[tex]s=12[/tex] represent the sample standard deviation
[tex]n=25[/tex] sample size
[tex]\mu_o =160[/tex] represent the value to test
[tex]\alpha=0.05[/tex] represent the significance level
t would represent the statistic
[tex]p_v[/tex] represent the p value
Hypothesis to test
We want to verify if the true mean is greater than 160, the system of hypothesis would be:
Null hypothesis:[tex]\mu \leq 160[/tex]
Alternative hypothesis:[tex]\mu > 160[/tex]
The statistic is given by:
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)
Replacing the info we got:
[tex]t=\frac{183-160}{\frac{12}{\sqrt{25}}}=9.58[/tex]
The degrees of freedom are given by:
[tex]df=n-1=25-1=24[/tex]
And the p value would be:
[tex]p_v =P(t_{(24)}>9.58)\approx 0[/tex]
Since the p value is very low at any significance level we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 160
Which is required for sexual reproduction?
Answer:
2 parents are required
Step-by-step explanation:
Answer:
semen.............
What is the measure of angle L in parallelogrami LMNO?
20°
30°
40°
50°
Answer:
40°
Step-by-step explanation:
2x = 3x - 20 add like terms
x = 20 and angle l is equal to 3x minus 20 so 3 × 20 - 20 = 40°
3
Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.
The product of (3 + 2) and a complex number is (17 + 71).
The complex number is
Answer:
5-i
Step-by-step explanation:
Product=multiplication
Let the complex number=x
(3+2i)*x=17+7i
x=17+7i / 3+2i
x=(17-7i)*(3-2i)/(3+2i)*(3+2i)
=51-34i+21i+14i^2 / 9+6i+6i+4i^2
=51+13i+14i^2 / 9+12i+4i^2
= (51+14 - 13i) / 13
= (65 -13i) / 13
= 65 / 13 - 13 i / 13
= 5 - i.
how many legs totally do five horses, two people,three children and five dogs have
someone answer this
Answer:
16
Step-by-step explanation:
The right triangle shown is a 30:60:90 triangle.
30:60:90 right triangles have a 1:sqrt(3):2 ratio between their sides.
Since the side opposite from the 30 degree is 8, and x is opposite from the 90 degree angle, 8 and x have a 1:2 ratio, or 8:16.
How can sums and differences of cubes be identified for factoring?
Answer:
Step-by-step explanation:
The sum of two perfect cubes breaks down into two factors, the first is the sum of their cube roots, and the second is made up of the square of the first root minus the product of both roots plus the square of the second root.
The difference of two perfect cubes is decomposed into two factors, the first is the difference of their cube roots, and the second is made up of the square of the first root plus the product of both roots plus the square of the second root.
I need help with this one
Answer:
-12
Step-by-step explanation:
which of the points shown below are on the line given by the equation y=3x?check all that apply.
Point A: (1,3)
Point B: (3,1)
Point C: (3,-1)
Point D: (-1,-3)
Answer:
Point A: (1,3)Point D: (-1,-3)Step-by-step explanation:
The value of y in the (x, y) pair must be 3 times the value of x if the point is to be on the line. That is the case for points A, D.
Analyze the diagram below and answer the question that follows.
What is (-2)+(-5) on a number line explained
Answer:
(-2)+(-5) = -7
Step-by-step explanation:
-2 + -5 = -7
but negative PLUS a negative equals a negative so the answer is going to be a negative, and just to keep in mind in the future that a negative PLUS a negative will give us a negative and negative TIMES a negative gives us a positive, and a positive PLUS a positive gives us a positive and a positive TIMES a positive gives us a positive and Negative times a positive equals a negative and negative PLUS a positive find the sum take the absolute value of each integer and then subtract the values.
The answer is -7 hope this helped! :)
Answer:
-7
Step-by-step explanation:
they add upp because they both negative
There are 20 pieces of fruit in a bowl and 5 of them are apples. What percent of the fruit are apples?
Step-by-step explanation:
20fruits=100%
5fruits=?
5x100/20 5fruitsx5%
=24%
the sum of the measures of the angles of any triangle is 180 degrees. in triangle ABC, angles A and B have the same measure, of bile the measure of angle C is 72 degrees larger than each of A and B. what are the measures of the three angles?
Answer:
A=36
B=36
C=108
Step-by-step explanation:
A =B
2A+C=180
C is greater than A
2A+(A+72) =180
SIMPLIFY
3A +72=180
-72 ON BOTH SIDES
3A=108
DIVIDE BY 3
A=36
SO
B=36
36 TIMES 2 IS 72
180-72=108
SO
C=108
hope this helps
Answer:
Angle C= 108
Angles A and B=36
Step-by-step explanation:
180-72=108
108-72= 36
Check
36+36=72
72+108=180
what is the solution for this equation [3y+7]=13
Answer:2
Step-by-step explanation:
3y+ 7= 13
3y= 13 - 7
3y= 6
Y = 6/3
Y= 2
3. In 28 days, a person saved $42. What was this person's
average daily savings?
Answer:
The average would be 42 / 28 = $1.50 / day.
Answer:
$1.50 per day
Step-by-step explanation:
Take the dollar amount and divide by the number of days
42 dollars / 28 days
1.50 dollars per day
$1.50 per day
Solve for n.
11(n – 1) + 35 = 3n
n = –6
n = –3
n = 3
n = 6
Answer:
[tex]n = - 3[/tex]
Second answer is correct
Step-by-step explanation:
[tex]11(n - 1) + 35 = 3n \\ 11n - 11 + 35 = 3n \\ 11n - 3n = 11 - 35 \\ 8n = - 24 \\ \frac{8n}{8} = \frac{ - 24}{8} \\ n = - 3[/tex]
hope this helps
brainliest appreciated
good luck! have a nice day!
Please help! Correct answer only, please! Consider the following table. A movie theatre is planning to increase each of their various ticket prices by $2. Which informational matrix operation below would correctly increase of their prices ticket prices by $2? A. B. C. D.
Answer: D
Step-by-step explanation:
In order to increase each ticket by $2, you are ADDING 2 to each value.
So you create a matrix of all 2's and add that to the given matrix.
[tex]\left[\begin{array}{cc}2&2\\2&2\\2&2\end{array}\right] +\left[\begin{array}{cc}8&10\\12&16\\6&8\end{array}\right]\quad =\quad \large \left[\begin{array}{cc}10&12\\14&18\\8&10\end{array}\right][/tex]
Answer:
Unit 8 test answers
Step-by-step explanation:
1: a.)3x4
2:b.)
3:a.)
4:b.)
5:c.) matrix CD would have the dimensions 7x7
6: a.)
7:67
8:c.)
9:b.) Scott sold 1 van
10:d.)
Find the distance between the pair of points: (9,−3) and (0,−10).
Answer:
√130 is the distance between (9,-3) (0,-10)
at a coffee shop, the first 100 customers’ orders were as follows
Answer:
81%
Step-by-step explanation:
22+5=27
22/27
Daniel deposits $300 into an account that earns 16% interest annually. Which equation can be used to model his account balance, y, after x years?
Answer:
[tex]y=300(1+0.16)^x[/tex]
Step-by-step explanation:
This account can be modeled using the compound interest formula.the compound interest formula is expressed as[tex]A= P(1+r )^t[/tex]
Where
A =final amount = y
P=initial principal balance = $300
r=interest rate = 16%= 0.16
t=number of time periods elapsed= x
Hence the equation to model his account balance/ final amount A (y) after time (x) years is
[tex]y=300(1+0.16)^x[/tex]
ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.
Answer:
B. (f - g)(x) = -3x² - x - 4
Step-by-step explanation:
→Set it up like so:
(-4x² - 6x - 1) - (-x² - 5x + 3)
→Distribute the -1 to (-x² - 5x + 3):
-4x² - 6x - 1 + x² + 5x - 3
→Add like terms (-4x² and x², -6x and 5x, -1 and -3):
-3x² - x - 4
(TEKS 2A.) EF has midpoint M (6,2) and F (12,-6). What is the coordinates of the endpoint E.
A (2,8)
C (0, 10)
B (18,-2)
D (18,-14)
Answer:
C (0, 10)
Step-by-step explanation:
The point E is (x,y)
The point F is (12,-6).
The midpoint between E and F is M(6,2).
Midpoint
Is the mean between the points of E and F.
x
[tex]\frac{x + 12}{2} = 6[/tex]
[tex]x + 12 = 12[/tex]
[tex]x = 0[/tex]
y
[tex]\frac{y - 6}{2} = 2[/tex]
[tex]y - 6 = 4[/tex]
[tex]y = 10[/tex]
So E(0, 10), which means that the correct answer is C.
My son and I are stuck on this one. Can anyone give some insight to this problem? Thank you.
Answer:
I made is clear for you, now you may match each one
Step-by-step explanation:
f(1)= 11, f(n)= 3*f(n-1)
11*3= 33, 33*3= 99, 99*3= 297, ...11, 33, 99, 297...⊕ middle
f(1)= -18, f(n)= f(n-1)+21
-18+21= 3, 3+21= 24, 24+21= 45, ...-18, 3, 24, 45, ...f(1)= -18, f(n)= f(n-1) + 22
-18+22= 4, 4+22= 26, 26+22= 48, ...-18, 4, 26, 48, ...f(1)= -18, f(n)= 2*f(n-1)
-18*2= -36, -36*2= -72, -72*2= -144, ...- 18, -36, -72, -144...⊕ bottom
f(1)= -18, f(n)= 6*f(n-1)
-18*6= -108, -108*6= -648, -648*6= -3888, ...- 18, - 108, - 648, -3888, ...⊕ top
f(1)= 11, f(n)= f(n-1) + 22
11+22= 33, 33+22= 55, 55+22= 77, ...11, 33, 55, 77, ...The model represents x? - 9x + 14
Which is a factor of x2 - 9x + 14?
OX-9
OX-2
O x + 5
+
+
+
+
+
+
O x +7
+
+
+
+
+
+
+
Answer:
work is shown and pictured
The factor of the equation x² - 9x + 14 is,
⇒ (x - 2)
What is an expression?Mathematical expression is defined as the collection of the numbers variables and functions by using operations like addition, subtraction, multiplication, and division.
Given that;
The equation is,
⇒ x² - 9x + 14
Now, We can find the factor of the expression as;
⇒ x² - 9x + 14
⇒ x² - 7x - 2x + 14
⇒ x (x - 7) - 2 (x - 7)
⇒ (x - 7) (x - 2)
Thus, The factor of the equation x² - 9x + 14 is,
⇒ (x - 2)
Learn more about the mathematical expression visit:
brainly.com/question/1859113
#SPJ7
The relationship between the number of pencil sharpener a company can sell each week and the price of each sharpener p is given by the equation x = 2300 − 100 p At what price should the sharpeners be sold if the weekly revenue is to be $ 12000
Answer:
The price p could be any of $8 or $15 .
Step-by-step explanation:
The equation is a relationship between the numbers of pencil sharpener x can sell each week and the price of each sharpener p.
x = 2300 - 100p
xp = 12000
therefore,
x = 12000/p
insert the value of x in the equation
x = 2300 - 100p
12000/p = 2300 - 100p
12000/p + 100p - 2300 = 0
multiply through by p
12000 + 100p² - 2300p = 0
100p² - 2300p + 12000 = 0
divide through by 100
p² - 23 + 120 = 0
Find the number that we can multiply to give 120 and add to give - 23. The number are -15 and - 8.
p² - 8p - 15p + 120 = 0
p(p - 8) - 15(p - 8) = 0
(p - 8)(p - 15)
p = 8 or 15
x = 2300 - 100p
x = 2300 - 100(8)
x = 2300 - 800
x = 1500 pencil sharpener sold
or
x = 2300 - 100(15)
x = 2300 - 1500
x = 800 pencil sharpener sold
The price could be any of $8 or $15 .
Ben scores 56 out of 79 marks in a maths test.
what is his score as a percentage to one decimal place