Answer:
The sum is 2. ...........
Answer:

Step-by-step explanation:
To find the matrix A, took all the numeric coefficient of the variables, the first column is for x, the second column for y, the third column for z and the last column for w:
![A=\left[\begin{array}{cccc}1&1&2&2\\-7&-3&5&-8\\4&1&1&1\\3&7&-1&1\end{array}\right]](https://tex.z-dn.net/?f=A%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%261%262%262%5C%5C-7%26-3%265%26-8%5C%5C4%261%261%261%5C%5C3%267%26-1%261%5Cend%7Barray%7D%5Cright%5D)
And the vector B is formed with the solution of each equation of the system:![b=\left[\begin{array}{c}3\\-3\\6\\1\end{array}\right]](https://tex.z-dn.net/?f=b%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D3%5C%5C-3%5C%5C6%5C%5C1%5Cend%7Barray%7D%5Cright%5D)
To apply the Cramer's rule, take the matrix A and replace the column assigned to the variable that you need to solve with the vector b, in this case, that would be the second column. This new matrix is going to be called
.
![A_{2}=\left[\begin{array}{cccc}1&3&2&2\\-7&-3&5&-8\\4&6&1&1\\3&1&-1&1\end{array}\right]](https://tex.z-dn.net/?f=A_%7B2%7D%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%263%262%262%5C%5C-7%26-3%265%26-8%5C%5C4%266%261%261%5C%5C3%261%26-1%261%5Cend%7Barray%7D%5Cright%5D)
The value of y using Cramer's rule is:

Find the value of the determinant of each matrix, and divide:


The dimensions of the rectangle are length 156 m and a width of 65m, and a perimeter P = 442m
<h3>How to find the dimensions of the rectangle?</h3>
For a rectangle of length L and width W, the diagonal is:

Here we know that the diagonal is 169m.
And the ratio of the length to the width is 12:5
This means that:
W = (5/12)*L
Replacing all that in the diagonal equation:

So the length is 156 meters, and the width is:
W = (5/12)*156 m = 65m
Finally, the perimeter is:
P = 2*(L + W) = 2*(156 m + 65m) = 442m
If you want to learn more about rectangles:
brainly.com/question/17297081
#SPJ1
solve for x.
4x−5=7+4y
Add 5 to both sides.
4x−5+5=4y+7+5
4x=4y+12
Divide both sides by 4.
4x/4=4y+12/4
x=y+3
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Have a nice day! :)
Answer:
Step-by-step explanation:
A