chứng minh mệnh đề sau bằng phương pháp phản chứng:
" Nếu phương trình bậc hai ax2+bx+c=0 vô nghiệm thì a và c cùng dấu"

Answers

Answer 1

Answer:

Which language is this ?????


Related Questions

Find the x and the y.
2x+y+79-x+4y=180

Answers

Answer:
x = − 5 y + 101

find five consecutive even integers preceding -35

Answers

Answer:

-44, -42, -40, -38, -36

Step-by-step explanation:

"preceding" requires an indication of the direction.

but I assume the usual left to right direction. in that sense the provided 5 even numbers are directly preceding -35

Venita is factoring the expression 32 a b minus 8 b. She determines the GCF and writes the factored expression as 8 b (4 a minus 0). Which best describes Venita’s error?

Answers

Answer:

8b(4a-1)

Step-by-step explanation:

32ab-8b

8b(4a-1)

Answer:

Did ur question get answered ??

Step-by-step explanation:

You and your best friend are both on the swim team. You want to beat your friend at the next swim meet so you decide to swim 15 minutes longer than she does one day at practice. Write an equation for the number of minutes you swim, y, when your friend swims x number of minutes. You swim 55 minutes. How many minutes did your friend swim?

Answers

Answer:

y=x+15

Friend swims 40 minutes

Step-by-step explanation:

We  re told that you want to swim 15 minutes longer than your friend. In word problems, longer or more always means addition. This means we will add 15 minutes to your friend's swim time (x) so we can figure out how long you swam (y).

This gives us the equation: y=x+15

Part two:

We know that you swam 55 minutes. This means y=55.

55=y=x+15

55=x+15

Now we want to get x alone, or isolate it. We can do this by subtracting 15 from both sides.

55-15=x+15-15

15-15= 0 and 55-15= 40

40=x

Thus your friend swam 40 minutes

(Remember that whatever you do to one side of the equation, you have to do to the other. If you add 2 to the left hand side, you have to add 2 to the right hand side. If you, like we did above, subtract 15 from the right, you have to subtract 15 from the left too)

factorise 1000a^2+27b^2​

Answers

1000a+27b with 2 on top of the number

use the ratio of a 45-45-99 triangle to solve for the variables.​

Answers

hopefully this answer can help you to answer the next question.

SEE QUESTION IN IMAGE

Answers

Answer:

20

Find the mean:

(2*1 + 1*2 + 2*3 + 1*4 + 2*5)/(2 + 1 + 2 + 1 + 2) = 3

Find the variance:

[2*(1-3)² + (2 - 3)² + 2*(3 - 3)² + (4 - 3)² + 2*(5 - 3)²]/8 = 18/8 = 9/421

Find the range:

10 - 2 = 8

Find the mean:

(2 + 3 + 4 + 5 + 6 + 6 + 7 + 8 + 9 + 10)/10 = 6

Find the variance:

[(2 - 6)² + (3 - 6)² + (4 - 6)² + (5 - 6)² + 2(6 - 6)² + (7 - 6)² + (8 - 6)² + (9 -6)² + (10 - 6)²]/10 = 6

The difference:

8- 6 = 222

The mean:

(0 + x + 2 + 3x + 6 + 4x + 8)/4 = 8

Find the value of x and the data points:

8x + 16 = 328x = 16x = 2

The points are:

0, 2 + 2 = 4, 3*2 + 6 = 12, 4*2 + 8 = 16

The mean deviation:

(0 - 8 + 4 - 8 + 12 - 8 + 16 - 8)/4 = 0

Note. Mean absolute deviation is different, this is the average of absolute values of mean deviations:

(8 + 4 + 4 + 8)/4 = 6

Match each equation with its solution


PLEASE HELPP ASAP!

Answers

Answer:

-5x = 26 is 5.2

x/2 = 4 is -8

3/2x=6 is 4

x/-7.2=4 is 28.8

Can u help solve this

Answers

Answer:

Sure:)! the answer is-487.5

Step-by-step explanation:

1.3x3xr^31.3x3=3.93.9r^3r=55x5x5=1253.9x125=487.5

As said in the problem pie=3 as determined in the problem. Hence, the answer is 487.5

Hope this helps :)!

Step-by-step explanation:

[tex]volume = \frac{4}{3} \pi \: {r}^{3} \\ = here\pi = 3 \\ then \: v = \frac{4}{3} \times 3 \times {5}^{3} \\ = 4 \times 125 \\ = 500 {in}^{3} \\ thank \: you[/tex]

Evaluate the following
expression using x = 6:
8(3x + 1)


Anyone know the answer

Answers

Answer:

152

Step-by-step explanation:

Substitute the given value for x.

[tex]8(3(6)+1)\\8(18+1)\\8(19)\\152[/tex]

Answer:

152

Step-by-step explanation:

8(3x+1)

Let x = 6

8(3*6+1)

Multiply inside the parentheses

8(18+1)

Add inside the parentheses

8(19)

Multiply

152

find length of missing sides ​

Answers

A 45-45-90 triangle follows a unique pattern. It has two congruent sides and one side that = x * sqrt(2).

If AC = 9sqrt(2), then AB is also 9sqrt(2).

To find CB, we need to multiply 9sqrt(2) by sqrt(2).

9sqrt(2) * sqrt(2) = 9 * 2 = 18

CB = 18

Hope this helps!

Use the product of powers property to simplify the expression -2x^3y4x^2y^3

Answers

Answer:

= -8x^5 y^4

Step-by-step explanation:

Multiply the numbers: -2 . 4 = -8

-2x^3 yx^2 y^3

Simplify x^3 x^2 : x^5

= -8x^5yy^3

Simplify yy^3 : y^4

= -8x^5 y^4

Numeric Response 4. In an arithmetic series, the first term is -12 and the 15th term is 40. The sum of the first 15 terms is (Record your answer in the numerical-response section below.)

Your answer should be in.0000​

Answers

In any artihmetic sequence, consecutive terms differ by a fixed constant c. So given the first term a, the second term is a + c, the third terms is a + 2c, and so on, up to the n-th term a + (n - 1)c.

If the 15th term is 40, then

40 = -12 + (15 - 1) c   ==>   c = 52/14 = 26/7

We can then write the n-th term as

-12 + (n - 1) 26/7 = (26n - 110)/7

The sum of the first 15 terms is then

[tex]\displaystyle \sum_{n=1}^{15}\frac{26n-110}7 = \frac{26}7\sum_{n=1}^{15}n - \frac{110}7\sum_{n=1}^{15}n = \boxed{210}[/tex]

Another way to compute the sum: let S denote the sum,

S = -12 - 58/7 - 32/7 + … + 228/7 + 254/7 + 40

Reverse the order of terms:

S* = 40 + 254/7 + 228/7 + … - 32/7 - 58/7 - 12

Notice that adding up terms in the same position gives the same result,

-12 + 40 = 28

-58/7 + 254/7 = 28

-32/7 + 228/7 = 28

so that

S + S* = 2S = 28 + 28 + 28 + … + 28 + 28 + 28

There are 15 terms in the sum, so

2S = 15×28   ==>   S = 15×28/2 = 210

NEED ASAP!!!

In this figure, AB || CD and m/_3=120
What is m/_6?
Enter your answer in the box​

Answers

Answer:

m/_6=60

Step-by-step explanation:

angles 3 and 6 are same side interior angles makeing them suplimentary.

180-/_3=/_6

180-120=60

it works both ways as well!

If 15 men can de a piece of work in 12 days, how many men will need to complete the samepiece of
work in 18 days?​

Answers

Answer:

10 men

Step-by-step explanation:

This is because men are inversly proportionate to days.

The more the days the lesser the men and bise versa.

This means 180 men can do a painting in one day and 10 men can do the painting in 18 days.

10 boys cleared a piece of land for 21 days how many days will it take 7 boys to clear the same land if they work at the same rate

Answers

Answer:

it took 7 boys 21 days to clear a piece of land.

Select the best answer to describe the parabola

Answers

Answer:

B

Step-by-step explanation:

It opens downwards, so the parabola is negative. This also means the vertex of the parabola is the highest point, therefore it is a maximum.

Art class has 444 tables. There are 999 pencils at each table.
Ava multiplied 4\times94×94, times, 9 to find the total number of pencils.
Finn multiplied 9\times49×49, times, 4 to find the total number of pencils.
Who is correct?
Choose 1 answer:

Answers

Answer:

Both Ava and Finn are correct

Step-by-step explanation:

There are 4 tables and 9 pencils at each table

4 ( 9) = 36

9 * 4 = 36

Both Ava and Finn are correct

please help!! geometry also might ask another question in the comments so be able to answer and I’ll mark you brainliest later :)

Answers

Coordinate of D: (2, -2)

Multiply x and y by 0.5

Answer: D = (1, -1)

After two people answer one of my questions, how do I give brainlyist to one of them?

Answers

Vas happenin!
Hope your day is going well

Once two people answer your question there at the top of the question that they answer should have a crown and the words mark the Brainliest. Then it will go yellow when you mark it and it will also give you points

do what you want ok and choose

NEED HELP IN FIVE MINUTE PLZ HURRY

Answers

Answer:

 R=.2,P=.25, G=.55

Step-by-step explanation:



The midpoint of AB is M(-6,1). If the coordinates of A are (-7, -3), what are
the coordinates of B?

Answers

Answer:

B = (1, -4)

Step-by-step explanation:

the midpoint formula is ((x1 + x2) / 2 , ( y1 + y2) / 2)

M = (-6,1) and A = (-7,-3)

if we make A (x1, y1), we can plug in and solve for B (x2, y2)

-7 + x2 = -6

x2 = 1

1 + y2 = -3

y2 = -4

B = (1, -4)

What are the factors of the expression below -2x^2+5-3


A -1(2x-3)(x-1)

B -1(2x+3)(x-1)

C -1(2x+3)(x+1)

D -1(2x-3)(x+1)

Answers

d got it right hope you do

Answer:

A

Step-by-step explanation:

Given

- 2x² + 5x - 3 ← factor out - 1 from each term

= - 1(2x² - 5x + 3) ← factor the quadratic

Consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term.

product = 2 × 3 = 6 and sum = - 5

The factors are - 2 and - 3

Use these factors to split the x- term

2x² - 2x - 3x + 3 ( factor the first/second and third/fourth terms )

2x(x - 1) - 3(x - 1) ← factor out (x - 1) from each term

(2x - 3)(x - 1)

Then

- 2x² + 5x - 3 = - 1(2x - 3)(x - 1) → A

Select the correct answer.

Which inequality represents all the solutions of 10(3x + 2) > 7(2x − 4)?

A.
x > -4
B.
x < -4
C.
x > -3
D.
x < -3

Answers

Answer:

C

Step-by-step explanation:

Given

10(3x + 2) > 7(2x - 4) ← distribute parenthesis on both sides

30x + 20 > 14x - 28 ( subtract 14x from both sides )

16x + 20 > - 28 ( subtract 20 from both sides )

16x > - 48 ( divide both sides by 16 )

x > - 3 → C

PLS PLS help me create a new polynomial identity ASAP!!!!!

(y+x) + (ax+b)

Square the expression on the left, then add the expression on the right.

Answers

Answer:

ax + b + y^2 + 2yx + x^2

Step-by-step explanation:

(y+x)^2

= (y+x)(y+x)

= y^2 + 2yx + x^2

y^2 + 2yx + x^2 + (ax+b)

= ax + b + y^2 + 2yx + x^2

please explain this to me?​

Answers

Answer:

14cm + 3cm =17cm

Step-by-step explanation:

now find the area

need help refer to picture

Answers

Answer:

203 ft.

Step-by-step explanation:

Since we are given the measurements of two sides, we can use trig to find the angle (or our reference angle, we'll call it x) the sides form.

SOH-CAH-TOA

We'll use cosine since the adjacent and hypotenuse were given for our reference angle.

Cos(x) = (adj/hyp)

Cos(x) = (396/445)

[Cos(x)]cos^-1 = (396/445)(cos^-1)

x ≈ 27.1409 (Nearest ten-thousandth)

And now we find the missing side using our now known angle.

SOH-CAH-TOA

Tan(x) = (opp/adj)

Tan(27.1409) = (opp/396)

0.5126 ≈ (opp/396)

(0.5126)(396) ≈ (opp/396)(396)

Opp = 203

Missing Side = 203 ft

The area CA) of a Parallelogram is found by using this formula A = BH What is the area when b is 7cm and h is 3cm?​

Answers

Answer:

Area of parallelogram = 21

Step-by-step explanation:

A = BH

Plug in

A = 7×3

Solve

A = 21

The answer will be 21.

2(2x+3)=3(3x+1)
Duýdhdhdjjdjdjđm

Answers

Answer:

12

Step-by-step explanation:

.......................

Answer:

x=1/2

Step-by-step explanation:

Answer the question

Answers

Answer:

1,041,958.5, or 104,195 1/2

Step-by-step explanation:

All you have to do is 15787.25 times 66, because 15787.25 is the price for on acre, so 66 acres will be 15787.25 times 66. If you want to put it in fraction form, you can do 15787 1/4 times 66. I hoped you liked this answer!

Other Questions
One card is randomly selected from a deck of cards. Find the odds against drawing a black 10.The odds against drawing a black ten are ___:___.(Simplify your answers.) A host is on the 192.168.146.0 network that has a subnet mask of 255.255.255.0. The binary value of the host portion is 11010101. What is the decimal value of the host portion of the address? Agile project management involves ____ whereas traditional project management involves _______. Multiple Choice known and stable scope, unknown requirements high certainty, projects with unstable scope projects with high predictability, project with unknown or unstable requirements iterative and incremental delivery, upfront planning with high predictability high uncertainty, projects with unknown requirements Jeff and his friends win a prize.Jeff's share is $160 which is of the prize.Work out the value of the prize. Anyone know how to make website (PROFESSIONAL) Arrange the following events in proper chronological order: Question: 71 of 73 a. The giving of the Law b. The atoning death of Christ c. Malachi prophesies d. The promise to Abraham e. creation and fall f. Pentecost g. Exile in Babylon h. David is King over Israel i. Paul is shipwrecked j. The Judges rule over Israel For the numbered steps below, select the option that places them in the correct order. 1) The ribosome binds to the mRNA and uses tRNAs to translate mRNA into the corresponding amino acid polypeptide sequence. 2) The spliceosome removes introns. 3) The primary structure of the polypeptide chain undergoes hierarchical foldings to form the tertiary structure. 4) RNA polymerase binds to the promoter region of a gene and initiates transcription. I / move / new school / English / taught / native teachers. A)I moved to a new school which English is taught with native teachers. B)I moved to a new school which English is taught by native teachers. C)I moved to a new school where English is taught with native teachers. D)I moved to a new school where English is taught by native teachers The isosceles triangle and rectangle have the same perimeter find the value of x Can someone help me out please Y=square root of x compare to y= - square root of x how they differ and why The volume of a 76.52 g sample of methane gas is 32.7 L at 26.9 C and 4.45 atm. What will its volume be at 95.4 C and 1.7 atm? porfavor es un cuadro quiero que me ayuden ILL MAKE U THE BRAINIEST Read the following excerpt from Thomas Paine's "Common Sense" and answer the question that follows:"But Britain is the parent country, say some. Then the more shame upon her conduct. Even brutes do not devour theiryoung, nor savages make war upon their families. Wherefore, the assertion, if true, turns to her reproach; but it happensnot to be true, or only partly so, and the phrase PARENT OR MOTHER COUNTRY hath been jesuitically adopted by theKing and his parasites, with a low papistical design of gaining an unfair bias on the credulous weakness of our minds.Europe, and not England, is the parent country of America. This new World hath been the asylum for the persecutedlovers of civil and religious liberty from EVERY PART of Europe."Why does Paine compare Britain to brutes and savages?A. To show how strong Britain isB. To show how caring and fair Britain isC. To show how cruel and unfair Britain isD. To show how weak Britain is A pyramid has a square base of length 4.8 m and a total surface area of 85 m. Find the volume of the pyramid. What is one point of view in Mein Kampf? Which of the following is not true if you default on a student loan?You may be taken to court and have to pay all fees,You may not be eligible for additional financial aid for future studies,Your tax refund may be withheld,You will have your passport taken away The following data from the just completed year are taken from the accounting records of Mason Company:Sales $656,000 Direct labor cost $80,000 Raw material purchases $135,000 Selling expenses $105,000 Administrative expenses $41,000 Manufacturing overhead applied to work in process $201,000 Actual manufacturing overhead costs $222,000Required:a. Prepare a schedule of cost of goods manufactured. Assume all raw materials used in production were direct materials.b. Prepare a schedule of cost of goods sold. Assume that the company's underapplied or overapplied overhead is closed to Cost of Goods Sold.c. Prepare an income statement. C quan im cho rng: Kinh t th trng nh hng x hi ch ngha Vit Nam thc cht l ang pht trin theo kinh t th trng ca ch ngha t bn. Quan im ng hay sai. Ti sao? Alicia was hoping to get promoted in the next 6 months. She had done all the things she thought she needed to do, and her boss had told her as much in their informal conversations. When her file went up for review, she was denied the promotion because there was no documentation of her achievements and performance on file. Though she appreciated informal praise for her work, what Alicia needed was