A 13​-pound mixture of coffee that contains both decaffeinated and regular coffee costs ​$34. The decaffeinated coffee costs ​$2 per​ pound, and the regular coffee costs ​$3 per pound. ​(a) Let x be the weight of the decaffeinated coffee and y be the weight of the regular coffee. Write a system of equations whose solution gives the amount of each type of coffee in the mixture. ​(b) Use the method of substitution to solve the system of equations.

Answers

Answer 1

Answer:

Weight of decaf coffee = 5 pounds.

Weight of regular coffee = 8 pounds.

Step-by-step explanation:

(a) Let x be the weight of decaf coffee and y the weight of regular coffee. Then:

x + y = 13

2x + 3y = 34

(b) From the first equation x = 13 - y, so substituting for x in second equation:

2(13 - y) + 3y = 34

26 - 2y + 3y = 34

y = 34 - 26 = 8.

Substituting for y in the first equation:

x + 8 = 13

x = 5.


Related Questions

Erin built a wooden box to hold hay on her farm. The box is 3 m long, 1 m wide, and 1 m high. Hay costs $14 per cubic meter.

Answers

Answer:

It will cost 42 to completely fill the box with hay.

have a good day <3

What function has zeros at x=10 and x=2

Answers

Answer:

  f(x) = x^2 -12x +20

Step-by-step explanation:

There are an infinite number of functions with zeros at those values of x. One simple polynomial function with those zeros is ...

  f(x) = (x -10)(x -2) . . . . . each zero contributes a factor

  f(x) = x^2 -12x +20

Thirty percent of students in a calculus class and twenty percent of students in a statistics course receive A’s. Furthermore, 60 percent of students with an A in calculus receive an A in the statistics course. What is the probability that a student who receives an A in statistics will also receive an A in calculus?

Answers

Answer:

90% probability that a student who receives an A in statistics will also receive an A in calculus

Step-by-step explanation:

We use the conditional probability formula to solve this question. It is

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]

In which

P(B|A) is the probability of event B happening, given that A happened.

[tex]P(A \cap B)[/tex] is the probability of both A and B happening.

P(A) is the probability of A happening.

In this question:

Event A: A in statistics.

Event B: A is calculus

Twenty percent of students in a statistics course receive A’s.

This means that [tex]P(A) = 0.2[/tex]

Furthermore, 60 percent of students with an A in calculus receive an A in the statistics course.

Thirty percent of students in a calculus class receive an A.

This means that [tex]P(A \cap B) = 0.6*0.3 = 0.18[/tex]

What is the probability that a student who receives an A in statistics will also receive an A in calculus?

[tex]P(B|A) = \frac{0.18}{0.2} = 0.9[/tex]

90% probability that a student who receives an A in statistics will also receive an A in calculus

Twenty words were randomly selected from two textbooks. Each set gives the number of letters in each of the twenty words for that textbook.




Briefly describe how the word lengths compare between textbook 2 and textbook 1.



Briefly describe the variability in the length of words in textbook 2 compared to textbook 1. PLEASE HURRY :(

Answers

Answer:

k = 13The smallest zero or root is x = -10

Step-by-step explanation:

you can write "x^2" to mean "x squared"

f(x) = x^2+3x-10

f(x+5) = (x+5)^2+3(x+5)-10 ... replace every x with x+5

f(x+5) = (x^2+10x+25)+3(x+5)-10

f(x+5) = x^2+10x+25+3x+15-10

f(x+5) = x^2+13x+30

Compare this with x^2+kx+30 and we see that k = 13

Factor and solve the equation below

x^2+13x+30 = 0

(x+10)(x+3) = 0

x+10 = 0 or x+3 = 0

x = -10 or x = -3

The smallest zero is x = -10 as its the left-most value on a number line.

The perimeter of a rectangle is 62 meters. The length is 4 more than 2 times the width. What is the length?

Answers

Answer:

4x+ 1 = 24 + 1 = 25 m.

Step-by-step explanation:

Given, perimeter = 62 m. Perimeter : 2 (L+W) = 62 m. hence, L+W = 31 m. x = 30/5

Answer:

Step-by-step explanation:

let width be x

length = 2x + 4

2(x + 2x + 4) = 62

6x + 8 = 62

6x = 54

x = 9

length = 2(9) + 4 = 22cm

if i'm 18 and my sister is 19, how much younger am I than she is?

Answers

it would be a year !

Answer:

one year

Step-by-step explanation:

Can you work out this math puzzle?

Answers

Triangle=10
Circle=5
Square:3.5
Half square:1.75
Answer to ?:26.25

The value of the puzzle is 17

The value of the triangle :

30/3 = 10

Value of Circle :

10/2 = 5

Value of whole yellow square :

8/2 = 4

Value of half-yellow square :

4/2 = 2

Using the above information:

Triangle + Circle + half-square

10 + 5 + 2 = 17

Therefore, the solution to the puzzle is 17

Learn more on puzzles : https://brainly.com/question/31416634

#SPJ6

0.6666666……… as a percentage

Answers

Answer:

2/3

Step-by-step explanation:

Answer: 66.66%

Step-by-step explanation: You multiply 0.66666... by 100 and that gives you 66.66

what’s the gcf of x^2 and 5x

Answers

Answer:

the GCF of x^2 and 5x is x

Find the prime factors of each term in order to find the greatest common factor (GCF).


There are 14 math teachers and 26 science teachers at
school today. What is the ratio of math teachers to math
and science teachers at school?​

Answers

Answer: 2.86

Step-by-step explanation:

14+26=40

40/14

Answer:

2.86

Step-by-step explanation:

Find the arc length of the partial circle. with a radius of 1

Answers

Answer:

1/2π

Step-by-step explanation:

For khan, you HAVE to put the pi symbol. just type pi and itll work

Answer:

1/2 pi (Sorry i don't have the pi symbol)

Step-by-step explanation:

1567÷135

plz help 50 points ​

Answers

Answer:

11.60740741

Step-by-step explanation:

Answer:

11.6074074074

Step-by-step explanation:

Simplifying products and quotients of powers

7^2•7^8/7^4=7^a/7^4=7^b

A=
b=

Answers

Answer:

a=10

b=6

Step-by-step explanation:

add 2 to 8, to get a, then subtract 4 from 10 to get b

Answer:

10 and 6

Step-by-step explanation:

What’s the correct answer for this?

Answers

Answer:

6 units

Step-by-step explanation:

We find the distance by subtracting the "ends"

=-4-2= -6 (ignoring the negative)

We get

=6

Please help ASAP! I will mark Brainliest! Please answer CORRECTLY! No guessing! Show your work!

Answers

Answer:

P represents the population in year 0

Step-by-step explanation:

The exponential growth function is f(x) = a (1 + r)^t, where a is the initial

amount (at t = 0), (1 + r) is the factor of growth , r is the rate of growth

in decimal ant is the time of growth

the function C(t) = P(1 + r)^t represents the population of

centerville at year t, where P is the initial population and r is the

rate of increase

If your investment is increased 10% annually, then that means

each year, your total has multiplied itself by 110% (the growth factor

is 1 + 10/100 = 1.1)

(1 + r) is the factor grows each year

C(t) = P(1 + r)^t

C depends on P(starting population) , r(the increasing rate and

t(the time in year)

r is the rate of increase means the percentage of increasing , then

0 < r < 1

r is not less than 0

P is the initial amount when t = 0

P represents the population in year 0

Answer:

P represents the population in year 0

Step-by-step explanation:

A medical researcher is studying the spread of a virus in a population of 1000 laboratory mice. During any week, there is an 80% probability that an infected mouse will overcome the virus, and during the same week there is a 10% probability that a noninfected mouse will become infected. Three hundred mice are currently infected with the virus. How many will be infected next week and in 3 weeks

Answers

Answer:

The number of mice that will be infected next week are 130 while

The number of mice that will be infected in 3 weeks are 111

Step-by-step explanation:

From the information given , the researcher is studying the spread of a virus in a population of 1000 laboratory mice. i.e, n = 1000

Number of infected = 300

Non infected = 1000 - 300 = 700

Probability an infected mouse will overcome = 80% = 0.8

Probability a noninfected mouse becomes infected = 10% = 0.10

The number of infected that will overcome = 0.8 * 300 = 240

The number of non infected that will become infected = 0.1 * 700 = 70

The number that will be infected on the first week =

300 - 240 + 70

= 130

Number that will be healthy on the first week =

700 + 240 - 70

= 870

Calculating for week 2:

The number of infected that will overcome = 0.8 * 130 = 104

The number of non infected that will become infected = 0.10 * 870 = 87

The number that will be infected on the second week =

130 - 104 + 87

= 113

Number that will be healthy on the second week =

870 + 107 - 87

= 887

Calculating for week 3:

The number of infected that will overcome = 0.8 * 113 = 90.4

The number of non infected that will become infected = 0.10 * 887 = 88.7

The number that will be infected on the third week =

113 - 90.4 + 88.7

= 111.3 ≈ 111

Number that will be healthy on the third week =

887 + 90.4 - 88.7

= 888.7 ≈ 889

From our calculations, the number of mice that will be infected next week are 130

The number of mice that will be infected in 3 weeks are 111

By which rule are these triangles congruent?

Answers

Answer:

Side-Side-Side is a rule used to prove whether a given set of triangles are congruent. The SSS rule states that: If three sides of one triangle are equal to three sides of another triangle, then the triangles are congruent.

Step-by-step explanation:

Answer:Side-Side-Side is a rule used to prove whether a given set of triangles are congruent. The SSS rule states that: If three sides of one triangle are equal to three sides of another triangle, then the triangles are congruent.

Step-by-step explanation:

help please quick 100 points quick tell me what to write please if you now how to do this

Answers

Answer:

8 footballs

18 basketballs

36 baseballs

24 softballs

Step-by-step explanation:

Let f = footballs

f = 8

Let b = basketballs

b = 2+2f = 2 +2(8) = 2 +16 = 18

Let B = baseballs

B = 5f -4 = 5(8) -4 = 40-4 = 36

Let s = softballs

s = 6+1/2B = 6+1/2(36) = 6+18 = 24

The total is 86

f+b+B +s = 86

8+18+36+24 = 86

86=86

There are 8 footballs.

Two more than twice the number of footballs are basketballs:

2f + 2 = b

f = number of footballs

b = number of basketballs

In the first statement, there are 8 footballs. So, f = 8

2(8) + 2 = b

16 + 2 = b

18 = b

Therefore, there are 18 basketballs.

Four less than 5 times the number of footballs are baseballs:

5f - 4 = a

f = number of footballs

a = number of baseballs

In the first statement, there are 8 footballs. So, f = 8

5(8) - 4 = a

40 - 4 = a

36 = a

Therefore, there are 36 baseballs.

Six more than half of the baseballs are softballs:

a/2 + 6 = s

a = number of baseballs

s = number of softballs

In the third statement, there are 36 baseballs. So, a = 36

(36)/2 + 6 = s

18 + 6 = s

24 = s

Therefore, there are 24 softballs.

Best of Luck!

Sara Bought a computer that was originally priced at $896.The computer was on sale for 12% off. When she bought the computer, a 7% tax was added to the sale price. How much did Sara spend on the computer. Round to the nearest cent!

Answers

Answer:

$733.29. Simply because you take $896•0.12 to find the 12% off and then you take that subtracted by the starting total. After you get the 12% off then you multiply that number by .07 to get the sales tax. After you find that then you add the number you got after multiplying to the number you got after taking off the 12%.

Step-by-step explanation:

Plane P cuts sphere o in a circle that has diameter
20. If the diameter of the sphere is 30, how far is the
plane from O?​

Answers

Answer:

  5√5 ≈ 11.18 units

Step-by-step explanation:

The Pythagorean theorem can be used to find the unknown leg of a triangle with hypotenuse 15 and one leg 10:

  d = √(15^2 -10^2) = 5√(3^2 -2^2) = 5√5

The plane is 5√5 units from the center of the sphere.

Write the perimeter of the floor plan shown as an algebraic expression in x.

Answers

Answer: 8+2x

Step-by-step explanation:

Hi, Perimeter is the distance around a two-dimensional shape.

To calculate it, we have to add all the side lengths of the figure. The missing side  is the ? side (right side). To obtain it we have to subtract the top right side length (2) to the left side length (12)

So, the expression is equal to:

P = 12+ (x-4) + (x-12) +2 +(12-2)

P = 12+ x - 4 +x -12+2 +10

P = 12-4-12+2+10+x+x

P =8+2x

I really need help!! HELP ASAP PLEASE!!!
Which figure has an area of 12 square units?


Answers

Answer:

Should be the bottom one

Step-by-step explanation:

You can find this by counting. It is the only one with 12 units.

Answer:

Step-by-step explanation:is number 4 i pick it and its correct

A North American company manufactures rivets for use in car production. A sample of forty rivets from the production line had mean 6.803 and standard deviation 0.275 (both in 1/100 of an inch). On communicating these results to the company headquarters in Europe, a request is made for the summary statistics to be converted into millimeters. Given that one inch is 2.538 centimeters, find the mean and standard deviation of the sample in millimeters. What is the mean in millimeters

Answers

Answer:

Mean = 1.73 mm

Standard deviation = 0.0698 mm

Step-by-step explanation:

Given:

Sample size, n = 40

Mean, u = 6.803

Standard deviation = 0.275

a) Given that one inch is 2.538 centimeters, to find the mean in millimeters we have:

[tex] 6.803 * \frac{1}{100} [/tex]

Converting to cm, we have:

[tex] 6.803 * \frac{1}{100} * 2.538 = 0.173 cm[/tex]

Converting to mm, we know 1cm = 10 mm,

0.173 * 10 = 1.73 mm

b) Given that one inch is 2.538 centimeters, to find the standard deviation in millimeters we have:

[tex] 0.275 * \frac{1}{100} [/tex]

Converting to cm, we have:

[tex] 0.275 * \frac{1}{100} * 2.538 = 0.00698 cm[/tex]

Converting to mm, we know 1cm = 10 mm,

0.00698 * 10 = 0.0698mm

In this exercise we have to use the knowledge of statistics to calculate the car production, so we have to:

Mean: [tex]1.73mm[/tex]Standard deviation: [tex]0.0698 mm[/tex]

Given the following information, we have:

Sample size n = 40 Mean u = 6.803 Standard deviation = 0.275

A) Find the convertion to the mean in milimeters, will be:

[tex]6.803*(1/100)*2.538=0.173 cm\\=1.73 mm[/tex]

B) Find the convertion to the stardard deviation in milimeters, will be:

[tex]0.275*(1/100)*2.538=0.00698\\=0.0698 mm[/tex]

See more about statistics at brainly.com/question/10951564

What is a Regression equation

Answers

Answer:

Regression equations can help you figure out if your data can be fit to an equation.This is extremely useful if you want to make predictions from your data- either future predictions or indications of past behavior.For example,you might want to know what your savings are going to be worth in the future.There are several types of regression equations,some of the more common include exponential and simoke linear regression.In elementary statistics,the regression equation you are most likely to come across is the linear form.

what type of function has a common rate of change

Answers

Answer:

  linear

Step-by-step explanation:

A linear function has a constant rate of change.

_____

The word "common" is usually used to refer to a shared characteristic of two or more entities. It would not ordinarily be used to describe a characteristic of one function. We're not quite sure what you mean by "has a common rate of change."

KARLA has spent $33 on food. She bought milk, cheese, and meat. The milk cost half as much as the cheese and the meat cost four times as much as the cheese. Which equation will help you find the cost of the cheese?

Answers

C+.5c+4c=$33 is the correct equation

30 points!
The soccer team knows that if they score at least 8 goals, they will win the game. Which of the following inequalities shows the number of goals the team needs to win.

g ≥ 8 goals

g < 8 goals

g > 8 goals

g ≤ 8 goals

Answers

Answer:

g≥8

Step-by-step explanation:

They need at least 8 goals

g≥8

Answer:

g ≥ 8 goals

Step-by-step explanation:

Atleast 8 means greater than or equal to 8

Parallel lines s and t are cut by a transversal, r.

Parallel lines s and t are cut by transversal r. Clockwise from top left, the angles formed with r and s are 1, 2, 3, 4; the angles formed with r and t are 5, 6, 7, 8.

If the measure of angle 1 is 68°, what is the measure of angle 5?
22°
68°
112°
158°

Answers

Answer:

68°

Step-by-step explanation:

Angles 1 and 5 are corresponding angles on parallel lines, hence they are equal

Answer:

B.

Step-by-step explanation:

9/4 - 4/3 plz help me

Answers

Answer:

11/12

Step-by-step explanation:

Find the common denominator.

4 and 3 both go into 12.

4 goes into twelve three times so multiply the denom and the num.

9/4 = 27/12

3 goes into twelve four times.

4/3 = 16/12

Subtract.

27/12-16/12

= 11/12

Answer: 11/12

Step-by-step explanation:

multiply 3 and 4 to get a common denominator.

multiply 3 by 9 and 4 by 4

this gets u 27/12 and 16/12

subtract.

11/12

A national organization has been working with utilities throughout the nation to find sites for large wind machines that generate electricity. Wind speeds must average more than 15 miles per hour (mph) for a site to be acceptable. Recently, the organization conducted wind speed tests at a particular site. Based on a sample of wind speed recordings (taken at random intervals), the wind speed at the site averaged with a standard deviation of To determine whether the site meets the organization's requirements, consider the test, where μ is the true mean wind speed at the site and Fill in the blanks. "A Type I error in the context of this problem is to conclude that the true mean wind speed at the site _____ 15 mph when it actually _____ 15 mph."

Answers

Answer:

"A Type I error in the context of this problem is to conclude that the true mean wind speed at the site is higher than 15 mph when it actually is not higher than 15 mph."

Step-by-step explanation:

A Type I error happens when a true null hypothesis is rejected.

In this case, as the claim that want to be tested is that the average wind speed is significantly higher than 15 mph, the null hypothesis has to state the opposite: the average wind speed is equal or less than 15 mph.

Then, with this null hypothesis, the Type I error implies a rejection of the hypothesis that the average wind speed is equal or less than 15 mph. This is equivalent to say that there is evidence that the average speed is significantly higher than 15 mph.

"A Type I error in the context of this problem is to conclude that the true mean wind speed at the site is higher than 15 mph when it actually is not higher than 15 mph."

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