All categories

2 years ago

X+y-z=5 -x-4y-8z=6 3x+5y-4z=-20

Mathematics

1 answer:

Juli2301 [7.4K]2 years ago

3 0

Answer:

x = 24.48, y = -15.52, z = 3.95 to the nearest hundredth.

Step-by-step explanation:

x+y-z=5 (a)

-x-4y-8z=6 (b)

3x+5y-4z=-20 (c)

Adding equations a and b:

-3y - 9z = 11 (d)

Now multiply equation b by 3:

-3x - 12y - 24z = 18 (e)

Adding c and e:

-7y - 28z = -2 (f) Multiply by 3 to give (g)

-3y - 9z = 11 (b) Multiply by -7 to give (h)

-21y - 84z = -6 (g)

21y + 63z = -77 (h) Adding g and h:

-21z = - 83

z = 3.952

and y is found bt substituting in equation d:

-3y - 9(3.952) = 11

y = ( 11 + 9(3.952) / -3

= -15.52.

Now find x by substituting for y an z in equation a:

x - 15.52 - 3.952 = 5

x = 5 + 15.52 + 3.952

= 24.476.

You might be interested in

What is the molar mass dinitrogen monoxide?

irakobra [83]

The molar mass of dinitrogen monoxide?

Is=N2O=(14×2)+16

=44g/mol

8 0

3 years ago

A study was designed to investigate the effects of two variables(1) a student's level of mathematical anxiety and (2) teachin

dimaraw [331]

Using Chebyshev's Theorem, considering a standard deviation of 40, we have that at least 75% of the students scored between 360 and 520.

<h3>What does Chebyshev’s Theorem state?</h3>

When we have no information about the population distribution, Chebyshev's Theorem is used. It states that:

At least 75% of the measures are within 2 standard deviations of the mean.

At least 89% of the measures are within 3 standard deviations of the mean.

An in general terms, the percentage of measures within k standard deviations of the mean is given by $100(1 - \frac{1}{k^{2}})$ .

In this problem, considering a standard deviation of 40, we have that:

440 - 2 x 40 = 360.

440 + 2 x 30 = 520.

Within 2 standard deviations of the mean, no information about the distribution, hence, at least 75% of the students scored between 360 and 520.

More can be learned about Chebyshev's Theorem at brainly.com/question/25303620

7 0

2 years ago

Which three of the following expenses can student aid cover? tuition television school supplies parties and socializing boarding

Hitman42 [59]

The tuition, school supplies, and boarding/housing for the expenses can student aid cover.

<h3>What is decision-making?</h3>

The process of making choice is by identifying the correct decision, gathering information, and assessing alternative solutions.

The following expenses can student aid cover.

A. Tuition - A student aid cover can be utilized to promote the tuition.

B. Television - There is no use of the student aid cover for selling the TV.

C. School supplies - We can use the face of the topper on the school supplies to promote schooling.

D. Parties and socializing - There is no need for student aid cover for parties and socializing.

E. Boarding or housing - We can use student aid cover to promote the hostel for the student.

More about the decision-making link is given below.

brainly.com/question/3369578

5 0

1 year ago

Write −12.405 as a mixed number in simplest form

serious [3.7K]

Answer:

$-12\frac{81}{200}$

Step-by-step explanation:

In the decimal of −12,405, leave the −12 and divide 405 by 1000 for now:

$\frac{81}{200} = \frac{405}{1000}$

Greatest Common Divisor [GCD]: 5

Finally, you attach this back to the −12, giving you $-12\frac{81}{200}$ .

I am joyous to assist you anytime.

3 0

2 years ago

Martha earned $180 during the summer doing chores. She bought 3 books worth $14 each using her chore money. How much money was l

Viktor [21]

Answer:

$138

Step-by-step explanation:

We can first turn the words into a mathematical equation by substituting words with the information we have:

Total earning - ( Price of three books)

$180 - (Price of one book x 3)

$180 - ($14 x 3)

Finally, after we have created the mathematical equation, we solve it!

$180 - ($14 x 3)

$180 - $42

$138

6 0

2 years ago