Solve: what is 32% of 60?

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

Henry's house weighs 65,000 pounds. He removes all of his belongings which weigh 5,000 pounds. Movers are using Crib Jacks to li

adell [148]

Since 1 ton is 2,000 lbs, each Crib Jack can life 30,000 lbs. It's going to take 2 Crib Jacks, because the extra 5,000 lbs in belongings were removed, leaving the house at a weight of 60,000 lbs.

7 0

3 years ago

Read 2 more answers

75% of students were boys. there 18 boys in the class wht is the total number of students

Kaylis [27]

Answer:

the answer is 24.

Step-by-step explanation:

5 0

3 years ago

Thomas had 120 chicks 2/5 part given to Luke 1/4 part given to John. how many chicks does Mr. Thomas have now?

OlgaM077 [116]