A triangle has sides 12, 14, and 25. Is it a right traingle?

When any number is multiplied by 6 adn the digits of the answer are added?

ycow [4]

The result is always divisible by 3.

4 0

2 years ago

An archaeologist descends 22 feet into a canyon then climbs up 15 feet what is his final position

andrew-mc [135]

He's 7 feet into the canyon ( -7 ).

3 0

3 years ago

-5x + 3(7x - 5)<br> Help???

Anna007 [38]

So here we just are gonna distribute and simplify.

7 0

2 years ago

Read 2 more answers

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

Simplify.<br><br> (0.4n)(16n)

BigorU [14]

=(0.4n)(16n)
multiply 0.4 & 16 and n & n
=(0.4*16)(n * n)
=6.4n^2

Hope this helps! :)

4 0

2 years ago