tìm m để phương trình có 1 nghiệm duy nhất
x+2y-2z=2
3x+7y-z=5
2x+4y+mz=7

Answers

Answer 1

Rewrite the system of equations in matrix form.

[tex]\begin{bmatrix}1&2&-2\\3&7&-1\\2&4&m\end{bmatrix} \mathbf x = \mathbf b[/tex]

This system has a unique solution [tex]\mathbf x = \mathbf A^{-1}\mathbf b[/tex] so long as the inverse of the coefficient matrix [tex]\mathbf A[/tex] exists. This is the case if the determinant is not zero.

We have

[tex]\det(\mathbf A) = m+4[/tex]

so the inverse, and hence a unique solution to the system of equations, exists as long as m ≠ -4.


Related Questions

An arrow is shot vertically upward from a platform 45 feet high at a rate of
132 ft/sec. Use the quadratic function h(t)=−16t2+132t+45 to find how long it will take the arrow to reach its maximum height, and then find the maximum height. Round to the nearest tenth.

Answers

Answer:

486 feet will reached after 5.25 seconds, when rounded to nearest tenth would be 5.3

Step-by-step explanation:

6-4x=12+2x

Solve for x

Answers

6-4X = 12 + 2X
+4X. +4X
6= 12 + 6X
-12. -12
-6 = 6X

X EQUALS -1!

a ratio is a comparison between two or more numbers or quantities

a. True
b. False​

Answers

The correct answer is true

Which of the following is equal to the expression below
(8 - 32014
A 40
B. 30
C 835
D. 1035

Answers

Answer:

C 835Which of the following is equal to the expression below

please help!

15 - (-20)

Answers

I think it should be 35
35, the two negatives cancel out if they are next to each other, making it a plus sign instead, so its 15 + 20 = 35

Use the figure below to find the values of x and y

Answers

Answer:

x=68 and y = 112

Step-by-step explanation:

angles of a triangle must equal 180, so

52°+60°+x°=180

112+x=180 <-- subtract 112 to get x on one side.

x=68

To solve for y, a straight line = 180 so

68+y=180 --> just subtract 180-68

y=112

A store is having a sale where movies are 15% off their original price a movie is on sale for 22.10$ what was the original price of the movie

Answers

Answer:

The answer is $26

Step-by-step explanation:

So, the price after the sale was $22.10 and to find the original price you have to divide the price by 1- the discount. So, I did $22.10/ 1-0.15. Then, I got $22.10/0.85 and then I divided them by each other and got $26.

Please find the correct answer will give high points, mark brainliest, give 4 stars, and hearts. PLS


Answers

Answer d is correct.
|0.35| is equal to 0.35, |-0.81| is equal to 0.81.
-|0.81| is equal to -0.81.
Answer d is correct because -|0.81| is equal to a negative number and is less than 0, and d is the only answer that states that

Can somebody please help this is honestly due tomorrow

Answers

Answer:

I am almost completely sure its 4.

Step-by-step explanation:

I dont mind brainiests by the way

In your own words what does pi 7 mean if it’s right I’ll give you brainliest

Answers

Answer:

10

Step-by-step explanation:

Maria finds a local gym that advertises 44 training sessions for $1393. Find the cost of 136 training sessions.

Answers

Answer:

$4305.60

Step-by-step explanation:

1393 divided by 44 = 31.6590909

that's how much for one training session

so to find the pay for 136 sessions you need to do 31.6590909 x 136

which is 4305.63636

if you round that, you get $4305.60

The perimeter of a triangle is 71 cm. If the longest side of the triangle is 8 cm longer than five times the shortest side and the third side is 7 cm less than four times the shortest side. How long is the longest side of the triangle?

Answers

Answer:

43 cm

Step-by-step explanation:

If the longest side of the triangle is 8 cm longer than five times the shortest side

5s + 8

the third side is 7 cm less than four times the shortest side

4s - 7

The perimeter of a triangle is 71 cm

s + (4s - 7) + (5s + 8) = 71

Combine like terms

10s + 1 = 71

Subtract 1 from both sides

10s = 70

divide both sides by 10

s = 7

---------------------------------

How long is the longest side of the triangle

5s + 8

5(7) + 8

35 + 8

43

This the right one click it so you can get it right

Answers

Answer:

The one highlighted yellow is the correct option

6 liters is to 72 km as 50 liters is to x km

Which of the functions below have period pie check all that apply

Answers

There is no photo attached.

A 6 sided die is rolled 2 times. What is the probability of getting a 1 both times ?

Answers

Answer:

Step-by-step explanation:  If you roll the die twice, the probability of getting a even number both times is (1/2)(1/2) ... A probability experiment consists of rolling a 6 sided die

Triangle ABC has coordinates A(-2, -3), B(1, 1), and C(2, -1). If the triangle is translated 1 unit right and 3 units up, what are the coordinates of A'?

Answers

Answer:

answeris: C.(-6,-9)➡(6-9)

Find the GFC of 72 and 64

Answers

Answer:

8

Step-by-step explanation:

GCF of 64 and 72 is 8.

I hope it helps you..

This is a glucose molecule. How many hydrogen atoms are in a molecule of glucose? A) 10. B) 11. C) 12. D) 13

Answers

Answer:

12 for sure

Step-by-step explanation:

I just know

What is the algebraic expression for the following word phrase: "the product of x and the sum of 2 and y"?

Answers

Answer:

x(2+y)

Step-by-step explanation:

sum of 2 and y=2+y

product of x=x times expression

:. Answer =x(2+y)

A

Triangle ABC is right-angled at A, and AD is the altitude from A to the hypotenuse BC.
Find x

Answers

Answer:

Step-by-step explanation:

5 x 6:30

Please help me :)
What is the solution to this system of equations?

Answers

Answer:

The answer is D

Step-by-step explanation:

Plug in the values and see which one is correct.

Which equation represents the data in the table shown?
A) y = -2x
B) y = 2x + 3
C) y = -2x + 3
D) y = -2x - 3

Answers

Answer:

C

Step-by-step explanation:

the y-axis is getting smaller by 2 so its -2 and the x-axis is getting bigger by 1 so its -2 times 1 which is -2 but then 0=3 so the equation would be y = -2 + 3 :)

Which table of ordered pairs represents a proportional relationship?
CS
Х
-2
-4
-6
у
4
16
36
х
-4
-6
-8
y
-8
-12
-18
Х
-3
-5
-7
y
5
3
1
X
-3
6
_9
у
12
24
36

Answers

Answer: A 2-column table with 3 rows.

Step-by-step explanation:

Find all factors of 27.​

Answers

Answer:

all the factors of 27 is 1, 3 ,9,and 27

1 , 3 , 9 , 27 hope that helps you

You charge $1625 on your credit card that adds 8.2% intere don't make any payments, what will your balance be after 4 years compounded continuously?"​

Answers

Answer:$2227.22

Step-by-step explanation: I answered your question in your comment. If its not right report it please.

This morning, Megan and her dad had smoothies for breakfast. Megan made her smoothie with 1 cup of mango and 3 cups of strawberries. Her dad made a giant smoothie with 2 cups of mango and 6 cups of strawberries. Did the smoothies have the same ratio of mango to strawberries?

Answers

Answer:

Yes.

Step-by-step explanation:

after how many years will £6,000.00 yield a simple interest of £900.00 at 3%​

Answers

Answer:

add 1 Century to divide £6 000 000

Answer:

the answer to your question is 105 I think sorry if it's not

A 6-pack of ice cream sandwiches costs $3.86. What is the unit price, rounded to the nearest cent?


Answers

Answer: so either .64 or , .66,

Step-by-step explanation:

divide 3.86 by 6

Use your work from above to find the sum of 501+502+503+…+800

Answers

Answer:

Step-by-step explanation:

Gauss n(n+1)/2

which is n? the last number of the sum

500(500 + 1)/2 = 125,250

800(800+1)/2 = 320,400

uh oh forgot to read the last one, give me a minute. done

(800 - 501 + 1)(800 + 501)/2

300(1301)/2 = 195,150

or

320,400 - 125,250 = 195,150

WHAT IS THE EQUATION IN SLOPE INTERCEPT FORM FOT THE LINE THAT PASSES THROUGH THE POINTS (2,-2) AND (-3,-17)

Answers

Answer:

y = 3x - 8

Step-by-step explanation:

to find slope the equation (y2 - y1) / (x2 - x1) is used

this means change of y over change of x

[-17 - (-2)] / (-3 - 2)

(-17 + 2) / -5

-15 / -5 = 3

the slope is 3

to find slope intercept form you must find the y intercept

using y = 3x + b and plugging things in we can find it

we can plug in the first point

-2 = 2(3) + b

b is your y intercept

-2 = 6 + b

b = -8

Answer:

y = 3/1x - 8

steps:

(2,-2) (-3, -17)

x1. y1. x2. y2

y2-y1

x2-x1

-17 - -2 = -15. = 3

-3-2. -5. 1

(2,-2)

y= mx + b

-2 = 3/1(2) + b

-2 = 6 + b

-6 -6

-8 = b

y = 3/1x - 8

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