Answer: 1 = 4.20, 2 = 8.40 3 = 12.60 4 = 16.80
This is a direct variation.
Step-by-step explanation:
Since you need an isolated variable to use the substitution method, we need to re-arrange one of the equations. This will probably be easiest to do with the first one.
Add 5y to both sides of the first equation.
x=10+5y
Now, in the second equation, put in 10+5y in any spot that has an x.
2(10+5y)-10y=20
Distribute the 2 to both numbers in the parenthesis.
20+10y-10y=20
Combine like terms.
20=20
This means that the two equations are actually the same. You can see this if you multiply the whole first equation by 2
2(x-5y=10)
2x-10y=20, which is the same as the second equation. Therefore, the two equations are actually the same one.
The row echelon form of the matrix is presented as follows;

<h3>What is the row echelon form of a matrix?</h3>
The row echelon form of a matrix has the rows consisting entirely of zeros at the bottom, and the first entry of a row that is not entirely zero is a one.
The given matrix is presented as follows;

The conditions of a matrix in the row echelon form are as follows;
- There are row having nonzero entries above the zero rows.
- The first nonzero entry in a nonzero row is a one.
- The location of the leading one in a nonzero row is to the left of the leading one in the next lower rows.
Dividing Row 1 by -3 gives:

Multiplying Row 1 by 2 and subtracting the result from Row 2 gives;

Subtracting Row 1 from Row 3 gives;

Adding Row 2 to Row 3 gives;

Dividing Row 2 by -2, and Row 3 by 18 gives;

The above matrix is in the row echelon form
Learn more about the row echelon form here:
brainly.com/question/14721322
#SPJ1
Answer:
14.6
Step-by-step explanation:
The area of a rectangle is area=length*width
so we can substitute the numbers here, 262.8=18w
divide 262.8 by 18 to isolate the variable.
You get 14.6.
The width is 14.6.