Ask question

Ask question

All categories

3 years ago

10

What is the answer A library contains 2000 books. There are 3 times as many non fiction books as fiction books. Write abd solve

a system of equations to determine the number of non fiction and fiction books.

1 answer:

Morgarella [4.7K]3 years ago

6 0

Answer:

There is 666.66666666 non fic, and 1333.33333334 fic

Step-by-step explanation:

You might be interested in

Simplify and factor if necessary

Dima020 [189]

Answer:

$\frac{1}{x}$

Step-by-step explanation:

$\frac{3x - 12}{3x^{2} - 12x}$

$\frac{3x - 12}{x(3x-12)}$ Factor out x.

$\frac{1}{x}$ Simplify.

4 0

2 years ago

Solve this system using matrices:

sweet [91]

Answer:

Step-by-step explanation:

A system of linear equations is one which may be written in the form

a11x1 + a12x2 + · · · + a1nxn = b1 (1)

a21x1 + a22x2 + · · · + a2nxn = b2 (2)

.

am1x1 + am2x2 + · · · + amnxn = bm (m)

Here, all of the coefficients aij and all of the right hand sides bi are assumed to be known constants. All of the

xi

’s are assumed to be unknowns, that we are to solve for. Note that every left hand side is a sum of terms of

the form constant × x

Solving Linear Systems of Equations

We now introduce, by way of several examples, the systematic procedure for solving systems of linear

equations.

Here is a system of three equations in three unknowns.

x1+ x2 + x3 = 4 (1)

x1+ 2x2 + 3x3 = 9 (2)

2x1+ 3x2 + x3 = 7 (3)

We can reduce the system down to two equations in two unknowns by using the first equation to solve for x1

in terms of x2 and x3

x1 = 4 − x2 − x3 (1’)

1

and substituting this solution into the remaining two equations

(2) (4 − x2 − x3) + 2x2+3x3 = 9 =⇒ x2+2x3 = 5

(3) 2(4 − x2 − x3) + 3x2+ x3 = 7 =⇒ x2− x3 = −1

8 0

4 years ago

Read 2 more answers

The number of hours spent per week on household chores by all adults has a mean of 28 hours and a standard deviation of 7 hours.

Alchen [17]

Answer:

Probability that the mean hours spent per week on household chores by a sample of 49 adults will be more than 26.75 is 0.89435.

Step-by-step explanation:

We are given that the number of hours spent per week on household chores by all adults has a mean of 28 hours and a standard deviation of 7 hours.

Also, sample of 49 adults is given.

<em>Let X = number of hours spent per week on household chores</em>

So, assuming data follows normal distribution; X ~ N( $\mu=28,\sigma^{2}=7^{2}$ )

The z score probability distribution for sample mean is given by;

Z = $\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\mu$ = mean hours = 28

$\sigma$ = standard deviation = 7 hours

n = sample of adults = 49

<em>Let </em> $\bar X$ <em> = sample mean hours spent per week on household chores</em>

So, probability that the mean hours spent per week on household chores by a sample of 49 adults will be more than 26.75 is given by =P( $\bar X$ > 26.75 hours)

P( $\bar X$ > 26.75 hours) = P( $\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n} } }$ > $\frac{26.75-28}{\frac{7}{\sqrt{49} } }$ ) = P(Z > -1.25) = P(Z < 1.25)

= 0.89435 {using z table}

Therefore, probability that the mean hours spent per week on household chores is more than 26.75 is 0.89435.

4 0

3 years ago

Read 2 more answers

Can Anyone Help Me

Studentka2010 [4]

A. True
.............

6 0

3 years ago

What’s the value of -3

tatiyna

Answer:

None

Step-by-step explanation:

5 0

4 years ago