<h2>
Answer:</h2>

<h2>
Step-by-step explanation:</h2>
We will use the Gaussian elimination method to solve this problem. To do so, let's follow the following steps:
Step 1: Let's multiply first equation by −2. Next, add the result to the second equation. So:

Step 2: Let's multiply first equation by −1. Next, add the result to the third equation. Thus:

Step 3: Let's multiply second equation by −35, Next, add the result to the third equation. Therefore:

Step 4: solve for z, then for y, then for x:


By substituting
into the first equation, we get the
. So:

Answer:
(17)
Sum of interior angles of a quadrilateral is 360°
- 110° + 130° + x + x - 3° = 360°
- 2x = 360° - 237°
- 2x = 123°
- x = 61.5°
(18)
Sum of interior angles of a hexagon is 180°*(6 - 2) = 720°
- 2*90° + 2x + 2(x + 22°) = 720°
- 90° + x + x + 22° = 360°
- 2x = 360° - 112°
- 2x = 248°
- x = 124°
(19)
Interior angles of a given pentagon are all marked as congruent, so the exterior angles are congruent too.
Sum of exterior angles is 360°.
Answer:
See explanation.
Step-by-step explanation:
An expression is a <u>set of terms that are combined using addition, subtraction, multiplication, or division.</u> The following are examples of expressions:



Note: expressions do not equal anything.
In contrast, equations are <u>expressions that equal at least one term.</u> The following are examples of equations:




Note: equations <u>do</u> equal a term, as shown in the examples.
Answer:
A and C
Step-by-step explanation:
Nothing much, just add 2 1/2 to 3 2/3 and subtract 2 1/2 from 3 2/3