1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Misha Larkins [42]
3 years ago
10

Adam and Barb planned a used book sale for the weekend so they gathered their books and agreed on a price for hardbacks and a lo

wer price for paperbacks. Adam sold 14 hardcover books and 20 paperbacks and earned $234 for his efforts. Barb sold 15 hardcover books and 9 paperbacks. Barb made $201. How much did they charge for each hardcover book and for each paperback?
You must show your work.

1) Mathematically what kind of problem is this called? (What concept did you apply to this problem that allowed you to solve it?)


2) Set up the problem showing the equations you’ll use. Please make sure you label or explain what your variables mean.



3) Show the math work to arrive at the answer. Please make it clear which price is hardcover and which is paperback.
Mathematics
2 answers:
monitta3 years ago
8 0

Answer:

Step-by-step explanation:

The text itself determined how to solve the problem.

Namely, two object are given in two relations and we conclude that we have two variables that we present with two equations.

We will take hardcover books as x and paperbacks as y.

First equation is  4x+10y=64

Second equation is  5x+7y=58

This is system of two linear equations with two variables

To solve this system we will use Gaussian agorithm with which we make

gradual elimination of the variables.

We will multiply first equation with number 4 and second with number (-5)

and get

20x+50y=320   and   -20x-28y=-232

When we add first equation to another we get

variable x is eliminated  

50y-28y=320-232 => 22y=88 => y=88/22=4

y=4  when we replace variable y in the first equation before multiplying

we get  4x+10*4=64 => 4x+40=64 => 4x=64-40 => 4x=24 => x=24/4=6

x=6

Total charge for hardcovers is  => 4x+5x=9x=9*6=54$

Total charge for paperbacks is => 10y+7y=17y=17*4=68$

Good luck!!!

Inessa [10]3 years ago
4 0

Answer: hardcover books x=11 and paperbacks y=4

Step-by-step explanation:

14x+20y=234

15x+9y=201

Multiply the top equation by 9 and the bottom equation by 20 so the outcome of both equations would be 126x+180y=2106 and 300x+180y=4020 then you subtract the two equations once you do that you get 174x=1914, and the y variable cancels out, once you divide 174 from 1914 you get 11x. So the answer for how much hardcover books cost is 11 dollars. Now we have to find the y variable which we can just plug in 11 (x) into the equation. So 15(11)+9y=201 we get 165+9y=201, subtract 165 from both sides and we get 9y=36 and divide 9 from both sides and we get 4 so y=4 the cost of paperbacks are 4 dollars

You might be interested in
Solve for x and y:
Pachacha [2.7K]

Answer:

A= I think because it is definite not c so there is a solution differently I know so that is my final answer.

Sorry if I am wrong.

4 0
3 years ago
The life of a semiconductor laser at a constant power is normally distributed with a mean of 7,000 hours and a standard deviatio
Scrat [10]

This question not incomplete

Complete Question

The life of a semiconductor laser at a constant power is normally distributed with a mean of 7,000 hours and a standard deviation of 600 hours. If three lasers are used in a product and they are assumed to fail independently, the probability that all three are still operating after 7,000 hours is closest to? Assuming percentile = 95%

Answer:

0.125

Step-by-step explanation:

Assuming for 95%

z score for 95th percentile = 1.645

We find the Probability using z table.

P(z = 1.645) = P( x ≤ 7000)

= P(x<Z) = 0.95

After 7000 hours = P > 7000

= 1 - P(x < 7000)

= 1 - 0.95

= 0.05

If three lasers are used in a product and they are assumed to fail independently, the probability that all three are still operating after 7,000 hours is calculated as:

(P > 7000)³

(0.05)³ = 0.125

7 0
3 years ago
Rent and other associated housing costs, such as utilities, are an important part of the estimated costs of attendance at colleg
zhenek [66]

Answer:

96% confidence interval estimate for the mean monthly rent of all unmarried BYU students in winter 2018 is  [335.89 , 356.10].

Step-by-step explanation:

We are given that a group of researchers at the BYU Off-Campus Housing department want to estimate the mean monthly rent that unmarried BYU students paid during winter 2018.

During March 2018, they randomly sampled 314 BYU students and found that on average, students paid $346 for rent with a standard deviation of $86.

So, the pivotal quantity for 95% confidence interval for the average age is given by;

           P.Q. = \frac{\bar X - \mu}{\frac{s}{\sqrt{n} } } ~ t_n_-_1

where, \bar X = average rent paid by 314 BYU students = $346

            s = sample standard deviation = $86

            n = sample of students = 314

            \mu = population mean monthly rent of all unmarried BYU students

So, 96% confidence interval for the population mean monthly rent, \mu is ;

P(-2.082 < t_3_1_3 < 2.082) = 0.96

P(-2.082 < \frac{\bar X - \mu}{\frac{s}{\sqrt{n} } } < 2.082) = 0.96

P( -2.082 \times {\frac{s}{\sqrt{n} } } < {\bar X - \mu} < 2.082 \times {\frac{s}{\sqrt{n} } } ) = 0.96

P( \bar X -2.082 \times {\frac{s}{\sqrt{n} } } < \mu < \bar X +2.082 \times {\frac{s}{\sqrt{n} } } ) = 0.96

96% confidence interval for \mu = [ \bar X -2.082 \times {\frac{s}{\sqrt{n} } } , \bar X +2.082 \times {\frac{s}{\sqrt{n} } } ]

                                                = [ 346 -2.082 \times {\frac{86}{\sqrt{314} } } , 346 +2.082 \times {\frac{86}{\sqrt{314} } } ]

                                                = [335.89 , 356.10]

Therefore, 96% confidence interval estimate for the mean monthly rent of all unmarried BYU students in winter 2018 is [335.89 , 356.10].

5 0
4 years ago
What is the solution to (5m)² - (2n-3m)³ if m=-3 and n=5
Nimfa-mama [501]

Answer:

-6634

Step-by-step explanation:

(5m)² - (2n-3m)³ if m=-3 and n=5

= (5 * (-3))^2 - (2 * 5 - 3 * (-3))^3

= (-15)^2 - (10 - (-9))^3

= 225 - (19)^3

= 225 - 6859

= -6634

7 0
3 years ago
3. find the domain and range of <br>a) 3x-2y+7=0<br>i think in y-intercept form it is y=3/2x + 7/2
bekas [8.4K]
3x-2y+7=0\\\\The\ slope-intercept\ form:\\\\2y=3x+7\ \ \ \ \ /:2\\\\y=\frac{3}{2}x+\frac{7}{2}\\\\The\ domain:x\in\mathbb{R}\\\\The\ range:y\in\mathbb{R}

3 0
3 years ago
Other questions:
  • PLEASE ANSWER! When a trinomial is factored as (x+m)(x+n), what is the sum of m and n?
    15·1 answer
  • Factor completely...................
    15·1 answer
  • What is the answer to this problem
    15·1 answer
  • Round 318.9 million to the nearest ten million
    12·1 answer
  • HELP HELP HELP HELP HELP
    9·2 answers
  • Anyone know dis, my brain is a cumwad rn
    8·2 answers
  • A stockbroker bought 55 shares of stock for $44.31 each.
    15·2 answers
  • HELP ASAP PLEASE AND SHOW WORK!!!
    9·1 answer
  • 3/2-(-3/4)+1/4 <br><br> solve please
    9·1 answer
  • Which of the following points has coordinates that are 5 horizontal units from point A
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!