phương pháp số bằng phương pháp khử gauss

[tex]\frac{11z}{z+3}=13-i,z\in\mathbb{C}[/tex]

First, multiply both sides by [tex]z+3[/tex],

[tex]11z=(13-i)(z+3)[/tex]

[tex]13z+39-iz-3i=11z[/tex]

Collect terms and put z on the left,

[tex]2z-iz=3i-39[/tex]

[tex]z(2-i)=3i-39[/tex]

[tex]z=\frac{3i-39}{2-i}[/tex]

Division of complex numbers is defined by multiplying both denominator and numerator with complex conjugate of the denominator,

[tex]z=3\frac{(i-13)(2+i)}{(2-i)(2+i)}[/tex]

Multiply out,

[tex]z=3\frac{2i-1-26-13i}{5}[/tex]

[tex]z=3\frac{-11i-27}{5}[/tex]

The result is,

[tex]z=-\frac{81}{5}-\frac{33}{5}i[/tex]

Hope this helps :)

Answer:

i. ans in picture

ii. ans in picture

iii. ans in picture

iv. 19

v. 38

Step-by-step explanation:

i. working in picture

ii. working in picture

iii. working in picture

iv.

180-90=90

90=2x+7+45=2x+52

2x=90-52=38

x=19

v.

angle COD=3x+10

180-3x+10-2x

180+10=2x+3x

190=5x

x=38

Answer:

Step-by-step explanation:

Apply the following triangle laws:

The sum of the angles of a triangle will always be 180 degrees.

Answer:

-27

Step-by-step explanation:

Let x = 6 and y = -3

[tex]-(6)+7(-3)\\-6-21\\-27[/tex]

Answer:

Step-by-step explanation:

Answer:

Step-by-step explanation:

The quadratic formula for a equation of form

ax²+bx + c = 0 is

[tex]x= \frac{-b +- \sqrt{b^2-4ac} }{2a}[/tex]

For the first equation,

x²+3x-4=0,

we can match that up with the form

ax²+bx + c = 0

to get that

ax² =  x²

divide both sides by x²

a=1

3x = bx

divide both sides by x

3 = b

-4 = c

. We can match this up because no constant multiplied by x could equal x² and no constant multiplied by another constant could equal x, so corresponding terms must match up.

Plugging our values into the equation, we get

[tex]x= \frac{-3 +- \sqrt{3^2-4(1)(-4)} }{2(1)} \\= \frac{-3+-\sqrt{25} }{2} \\ = \frac{-3+-5}{2} \\= -8/2 or 2/2\\= -4 or 1[/tex]

as our possible solutions

Plugging our values back into the equation, x²+3x-4=0, we see that both f(-4) and f(1) are equal to 0. Therefore, this has 2 real solutions.

Next, we have

x²+3x+4=0

Matching coefficients up, we can see that a = 1, b=3, and c=4. The quadratic equation is thus

[tex]x= \frac{-3 +- \sqrt{3^2-4(1)(4)} }{2(1)}\\= \frac{-3 +- \sqrt{9-16} }{2}\\= \frac{-3 +- \sqrt{-7} }{2}\\[/tex]

Because √-7 is not a real number, this has no real solutions. However,

(-3 + √-7)/2 and (-3 - √-7)/2 are both possible complex solutions, so this has two complex solutions

Finally, for

4x² + 1= 4x,

we can start by subtracting 4x from both sides to maintain the desired form, resulting in

4x²-4x+1=0

Then, a=4, b=-4, and c=1, making our equation

[tex]x=\frac{-(-4) +- \sqrt{(-4)^2-4(4)(1)} }{2(4)} \\= \frac{4+-\sqrt{16-16} }{8} \\= \frac{4+-0}{8} \\= 1/2[/tex]

Plugging 1/2 into 4x²+1=4x, this works as the only solution. This equation has one real solution

Answer:

x = 2515

Step-by-step explanation:

5000 = 2x - 30

2800 = x

140 kilograms of corn is needed to feed 2800 chickens.

Equation modelling is the process of writing a mathematical verbal expression in the form of a mathematical expression for correct analysis, observations and results of the given problem.

We have the number of kilograms of corn needed to feed 5000 chickens is 30 less than twice the number of kilograms needed to feed 2800 chickens.

Assume that [x] kilograms of corn is needed to feed 2800 chickens.

for 2800 chickens → [x] Kg of corn is needed

for 1 chicken → [x/2800] Kg of corn is needed.

So, we can write -

5000 × [x/2800] = 2x - 30

50x/28 = 2x - 30

50x = 28(2x - 30)

50x = 56x - 28 x 30

50x - 56x = - 840

- 6x = - 840

6x = 840

x = 140

Therefore, 140 kilograms of corn is needed to feed 2800 chickens.

To solve more questions on Equation Modelling, visit the link below -

brainly.com/question/14441381

#SPJ2

the trip to the airport was 6.25 miles.

Answer:

450 people

Step-by-step explanation:

The number of people running a race this year will be 450.

Mathematical expression is the combination of numerical variables and operations denoted by addition, subtraction, multiplication, and division signs.

Mathematical symbols can be used to represent numbers (constants), variables, operations, functions, brackets, punctuation, and grouping. They can also be used to denote the logical syntax's operation order and other properties.

Given that last year, Rob set up the Road Runner Race for his school. The race was 1,200 meters long and 188 people signed up to run the race. 38 people did not show up to run. This year, there will be 3 times as many runners as last year.

The number of people running a race this year:-

Number = ( 188 - 38 ) x 3

Number = 150 x 3

Number = 450

Therefore, the number of people running a race this year will be 450.

To know more about an expression follow

https://brainly.com/question/22880916

#SPJ2

9514 1404 393

Answer:

  a.

Step-by-step explanation:

For an even-index radical, ...

  [tex]\sqrt[n]{x^n}=|x|\qquad\text{n even}[/tex]

This lets us simplify the given expression as follows:

  [tex]\sqrt[4]{81x^6y^4}-|y|\sqrt[4]{x^6}-\sqrt[4]{16x^2}=\sqrt[4]{(3xy)^4x^2}-|y|\sqrt[4]{x^4x^2}-\sqrt[4]{2^4x^2}\\\\=3|xy|\sqrt[4]{x^2}-|xy|\sqrt[4]{x^2}-2\sqrt[4]{x^2}=\boxed{2|xy|\sqrt[4]{x^2}-2\sqrt[4]{x^2}}[/tex]

Answer:

D

Step-by-step explanation:

-13.4 => 6.7+4.3+w

-13.4-6.7-4.3 => w

-24.4 => w

Answer:

D.

Step-by-step explanation:

5/4=1.25, -2[tex]\sqrt{2}[/tex] = -2.828

Therefore,

1.25 (5/4), 1.04, -0.34, -2.828 (-2[tex]\sqrt{2}[/tex]), -17

Answer:

1000

Step-by-step explanation:

35^2: 1225

15^2: 225

1225 - 225

Answer:

15

Step-by-step explanation:

Complementary angles add to 90 degrees

8x+27 + 6x-21 = 90

Combine like terms

14x+6 = 90

Subtract 6 from each side

14x+6-6 = 90-6

14x = 84

Divide by 14

14x/14 = 84/14

x=6

We want angle B

B = 6x-21 = 6*6-21 =36-21 = 15

Answer:

Step-by-step explanation:

I think the answer should be that there is an if -- then way the statement is worded. Quite often if then statements are used in this kind of experiment. Beyond that I can't make any comment. I don't know that it truly is testable, but it sounds like it should be.

Answer:

The hypothesis includes an explanation and makes a prediction.

Step-by-step explanation: I took the quiz on primavera and got that answer

Step-by-step explanation:

When I was a kid, the inch was a different length than the inch of today. Back then, there were approximately 39.36 inches in one meter. I had no trouble memorizing that number and still use it today, even though the number today is actually 39.37 inches (plus a tiny amount extra).

Today, the inch is defined to be exactly 2.54 centimeters long, so if we want to know exactly how many inches are in the meter, we would divide the number of centimeters in one meter by the number of centimeters in one inch.

[math]\frac{100\,cm\,per\,meter}{2.54\,cm\,per\,inch}\,=\,\frac{100}{2.54}[/math] inches per meter

My Windows calculator says that this is equal to:

39.37007874015748031496062992126…

I recommend memorizing the number 39.37.

As long as you memorize the fact that there are 2.54 centimeters in one inch, you can always use your calculator to get the approximate number of inches in one meter.

Addendum:

The old Mendenhall inch (1893) was exactly 39.37 inches per meter. The international inch, 0.0254 m, gives 39.37 and a bit. Total change is 2 parts per million. 

Answer:

3936 inches

Step-by-step explanation:

39.36 x 100 since each meter is 39.36 inches

Answer:

4.13=4.130

If there is a 0 at the end of a decimal then you can drop it.

The statement that correctly compares two numbers is 4.13 = 4.130. The correct option is A.

Expression in maths is defined as the collection of numbers variables and functions by using signs like addition, subtraction, multiplication, and division.

Numbers (constants), variables, operations, functions, brackets, punctuation, and grouping can all be represented by mathematical symbols, which can also be used to indicate the logical syntax's order of operations and other features.

From the given options the correct expression which represents equality will be 4.13 = 4.130. The value of both the numbers is the same. There is not any significance of 0 at the end of the expression.

Therefore, the statement that correctly compares two numbers is 4.13 = 4.130. The correct option is A.

To know more about an expression follow

https://brainly.com/question/28040125

#SPJ2

Answer:

Step-by-step explanation:

-8 *  9 * 1

If you are going to get - 72, you need to have an odd number of minus signs.

4 * 3 * - 6

You must be careful of the limits. You can't use something like 36 * 2  * 1 because the numbers don't fall within +/- 10

You could use 6*6*-2

Answer: 6 m

A ball thrown upwards from the altitude 4 m,

hits a roof and returns back to the ground.

upward movement:  s= −t²+3t+4

downward movement: s=-2t²+t+7

Step-by-step explanation:

Let's calculate the intersection:

[tex]- t^2+3t+4 =-2t^2+t+7\\\\t^2+2t-3=0\\\\t^2+3t-t-3=0\\\\t(t+3)-(t+3)=0\\\\(t+3)(t-1)=0\\\\t=-3 \ (exclude)\ or\ t=1\\\\if\ t=1 \ then\ s=-1^2+3*1+4=6\\\\height\ is\ 6\ m.\\[/tex]

Sorry, i have forgotten the picture.

Whole numbers are natural numbers, and natural numbers do not include negatives, decimals, fractions, or roots, so all whole numbers can indeed satisfy the inequality.

Please Mark my answer brilliant

Answer:

8:6

or

4:3

Step-by-step explanation:

Given that the height of a object thrown within a gravitational field is given as a quadratic equation in time, t, the time at which the object is at a specified height can be found by the quadratic formula

The values of, t, for which the height of the rocket is 82 feet are;

t = 12.21 seconds or t = 0.42 seconds

Question: Parts of the question that appear missing but can be found online are (i) To find the values of the time, t, when the rocket's height is 82 feet and round answers to the nearest hundredth

The known parameters of the rocket are;

The initial upward velocity of the rocket, v = 202 ft./s

The given function representing the height, h, (in feet) after t seconds is presented as follows;

H = 202·t - 16·t²

The unknown;

The time for which the height of the rocket is 82 feet

Method;

Substitute H = 82 feet in the height function equation and solve for t as follows;

When H = 82, we get;

82 = 202·t - 16·t²

Therefore;

16·t² - 202·t + 82 = 0

Dividing the above equation by 2 gives;

(16·t² - 202·t + 82)/2 = 0/2

8·t² - 101·t + 41 = 0

By using the quadratic formula, we get;

[tex]\mathbf{t = \dfrac{101 \pm \sqrt{(-101)^2 - 4 \times 8 \times 41} }{2 \times 8} = \dfrac{101 \pm \sqrt{8889} }{16}}[/tex]

Therefore, the values of t given by rounding off to the nearest hundredth are;

t = 12.21 or t = 0.42

The values of the time, t, at which the height of the rocket is 82 feet are t = 12.21 seconds or t = 0.42 seconds

Learn more about equation models of height as a function of time here;

https://brainly.com/question/84352

9514 1404 393

Answer:

Step-by-step explanation:

If Charles is 22 years older, he will be double Danielle's age when she is 22. If that is 10 years from now, Danielle is 12 and Charles is 34.

Answer:

Below.

Step-by-step explanation:

Area = 5(x + 3)

= 5x + 15

Perimeter = 2(x + 3) + 2(5)

= 2x + 6 + 10

= 2x + 16.

Answer:

y=3/2x^2+4x-2

Hope it helps

Answer:

16 ft

Step-by-step explanation:

Each edge of wall = √256 ft = 16 ft

Answer:

[tex]2x \times 2x - 3 \times 2x \times 4 \\ = 4 {x}^{2} - 24x \\ = 4( {x}^{2} - 6) \\thank \: you [/tex]

Answer:

f'(1) = 7/2

Step-by-step explanation:

We are given the function: [tex]f'(x)=\frac{7}{2\sqrt{x} }[/tex]

To find f'(1), substitute the value for x and evaluate it.

[tex]f'(1)=\frac{7}{2\sqrt{1} }\\\\f'(1)=\frac{7}{2(1)}\\\\f'(1)=\frac{7}{2}[/tex]

Therefore, f'(1) = 7/2.