A. Determine if the given figure is a polygon or not. Write P if it is a polygon and NP if it is not.
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Polygon: "a plane figure with at least three straight sides and angles, and typically five or more."

1. P

2. NP

3. P

4. NP

5. P

"A planar polygon is convex if it contains all the line segments connecting any pair of its points."

1. C

2. NC

3. NC

4. C

5. NC

Answers:

The first and third options should be selected.

The ordered pair (10,5) is a solution to the first equation because it makes the first equation true. The ordered pair (10,5) is not a solution to the system because it makes at least one of the equations false.

Explanation:

In order for a point to be a solution to a system of equations, it must make both equations true when its x and y values are substituted in. That being said, we need to test if (10,5) is a solution for the two equations.

Let's try the first equation. Substitute 10 for x and 5 for y and solve:

-5 does equal -5, so (10,5) is a solution to the first equation.

Next, let's test the second equation. Do the same:

However, 20 does not equal 11, therefore (10,5) is not a solution to the second equation.

So far, we know that (10,5) is a solution to the first equation, but not the second equation. Knowing this, it cannot  be a solution to the system because it does not make both equations true. Therefore, only the first and third options should be selected.