HERE IS THE ONE WITH THE QUESTION LOL PLZ ANSWER

Elaine walks her dog 2 times a day. Her walk in the evening is 2.5 times as far as her morning walk. At the end of the week she

Helen [10]

Answer:Add me on fortnite ill clap you

Step-by-step explanation:

7 0

2 years ago

Write the sentence as an equation.<br> 102 is the same as the product of 189 and p, decreased by 80

rosijanka [135]

Answer:

102+189p-80

Step-by-step explanation:

8 0

2 years ago

What is 73.31 rounded to the nearest tenth

blondinia [14]

73.3 is 73.31 rounded to the nearest tenth

4 0

3 years ago

Read 2 more answers

What is the equation of the line?

gizmo_the_mogwai [7]

undefined

y=undefined

4 0

3 years ago

Help please!!!!!!!!!

In-s [12.5K]

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 $C_{11} = M_{11} = 24$

4 0

3 years ago