1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
beks73 [17]
3 years ago
10

Help please!!!!!!!!!

Mathematics
1 answer:
In-s [12.5K]3 years ago
4 0

ANSWER

24


EXPLANATION

For a matrix A of order n×n, the cofactor C_{ij} of element a_{ij} is defined to be


   C_{ij} = (-1)^{i+j} M_{ij}


M_{ij} is the minor of element a_{ij} equal to the determinant of the matrix we get by taking matrix A and deleting row i and column j.


Here, we have


   C_{11} = (-1)^{1+1} M_{11} = M_{11}


M₁₁ is the determinant of the matrix that is matrix A with row 1 and column 1 removed. The bold entries are the row and the column we delete.


   \begin{aligned} A=\begin{bmatrix} \bf 1 & \bf -6 & \bf -4\\ \bf 7 & 0 & -3 \\ \bf -9 & 8 & -8 \end{bmatrix} \implies M_{11} &= \text{det}\left(\begin{bmatrix} 0&-3 \\ 8&-8 \end{bmatrix} \right)  \end{aligned}


Since the determinant of a 2×2 matrix is


   \det\left(  \begin{bmatrix} a & b \\ c& d  \end{bmatrix} \right) = ad-bc


it follows that


   \begin{aligned} A=\begin{bmatrix} \bf 1 & \bf -6 & \bf -4\\ \bf 7 & 0 & -3 \\ \bf -9 & 8 & -8 \end{bmatrix} \implies M_{11} &= \text{det}\left(\begin{bmatrix} 0&-3 \\ 8&-8 \end{bmatrix} \right) \\ &= (0)(-8) - (-3)(8) \\ &= -(-24) \\ &= 24 \end{aligned}


so C_{11} = M_{11} = 24

You might be interested in
Pls help me with this
scoundrel [369]

Answer:

6mm

Step-by-step explanation:

7 0
2 years ago
A rotation maps point A to A’.
weeeeeb [17]

Answer:  The answer is (C) 180° rotation.

Step-by-step explanation:  Given that the point A maps to the point A' by a rotation. We are to select the statement that describes the rotation.

In the given figure, the co-ordinates of point A are (-3, 5) and after rotation, the co-ordinates of point A' are (3, -5).

Therefore, the point (x, y) changes to (-x, -y) after rotation. This is the result of 180° rotation.

Therefore, the point A is rotated through an angle of 180° to reach at the point A'.

Thus, the correct option is (C) 180° rotation.

5 0
3 years ago
Read 2 more answers
Ethan wants to buy a new watch that cost $112. He pays 0.04 in interest for every $1 that he spends on his credit card. How much
valentina_108 [34]

Answer:

4.48

Step-by-step explanation:

112 x 0.04 = 4.48

3 0
2 years ago
Slope of the line (15,20),(-1,11)
masya89 [10]

Answer:

Slope, Angle, & Distance:

Slope: 0.5625

The slope of the line connecting (15, 20) and (-1, 11) is 0.5625

Slope (m): 0.5625

Angle (θ): 29.3578°

Distance: 18.3576

Δx: 16

Δy: 9

Slope Intercept Form:

(y = mx + b)

y = 0.5625x + 11.5625

Step-by-step explanation:

Steps to Find Slope

Start with the slope formula

m=

(y2 - y1)

(x2 - x1)

Substitute point values in the formula

m=

(11 - 20)

(-1 - 15)

Simplify each side of the equation

m=

(11 - 20)

(-1 - 15)

=

-9

-16

Solve for slope (m)

m=0.5625

<h2><em><u>Brainliest?</u></em></h2>
7 0
2 years ago
What type of tax is generally determined by the individual taxpayer?
wel

Answer:

I believe that it is income tax.

Step-by-step explanation:

3 0
2 years ago
Read 2 more answers
Other questions:
  • If my equation was <br> 8x5+4x2+3x2<br> How would I write it with parenthesis?
    12·2 answers
  • I NEED THIS ASAP PLEASE !!! I’ll make you the brainliest
    6·1 answer
  • HELP! what is the measure of uv
    9·1 answer
  • On a flight from New York to London, an airplane travels at a constant speed. An equation relating the distance traveled in mile
    9·1 answer
  • At a pumpkin patch, if Armando guesses the weight of his pumpkin within 0.3 pounds, he gets to take the pumpkin home for free. I
    14·2 answers
  • "Name the property:<br>a + (b+12) = (a+b) + 12"
    5·1 answer
  • PLEASSSEEEE HELPPPP
    6·1 answer
  • +12=15 pls tell me it’s for a grade
    15·1 answer
  • Passes through (-1, 4) and m=4
    10·1 answer
  • 35. the set, s consists of 900,000,000 whole numbers, each being the same number of digits long. howmany digits long is a number
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!