To find the area of a circle, you do π × diameter (in this case 10). They have told you to use 3.142 as π, so you do 3.142 × 10 = 31.42. Because it's a semi-circle, you need to halve 31.42 to get 16.21, which is the answer
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:
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Answer:
For children ages 2 to 5, limit screen time to one hour a day of high-quality programming. As your child grows, a one-size-fits-all approach doesn't work as well. You'll need to decide how much media to let your child use each day and what's appropriate.
Step-by-step explanation:
For kids aged 2 to 5, screen time should be limited to 1 hour per day, and parents should watch the programs with their child. Also, parents should have times when screens are turned off, and bedrooms should be media-free.
x = 12 , y = 18 (12, 18) is the solution, intersection of the two lines.
Answer: 13/7 or as a decimal 1.857142857
How did i get the answer:
Step 1: Simplify both sides of the equation.
so 1/2 of 10 is 5, 1/2 of 16 is 8
-3/5 of 15 is -9 and -3/5 of -35 is POSITIVE 21
all together should look like 5x+8+−13=−9x+21
(now we have to combine like terms)
8+ -13= -5
5x -5 = -9x+21
Step 2: Add 9x to both sides
5x + 9x= 14x
14x -5 = 21
Step 3: Add 5 to both sides.
21+5= 26
14x=26
Step 4: Divide both sides by 14.
26/14= 1.85714286 or 13/7