Answer:

General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtraction Property of Equality
<u>Algebra I</u>
- Terms/Coefficients
- Factoring
<u>Algebra II</u>
- Exponential Rule [Powering]:

- Solving exponential equations
Step-by-step explanation:
<u>Step 1: Define</u>
<em>Identify</em>
<em />
<em />
<em />
<u>Step 2: Solve for </u><em><u>x</u></em>
- Rewrite:

- Set:

- Factor:

- [Division Property of Equality] Divide 3 on both sides:

- [Subtraction Property of Equality] Subtract 3x on both sides:

- [Subtraction Property of Equality] Subtract 6 on both sides:

- [Division Property of Equality] Divide -1 on both sides:

4+5=9 divided by 3 is 3 times 4 is 12. so it's 12
hope this helps;)
Answer:
the first one since it shows all the lines being equal and therefore making the angles equal
It's hard to help if you can't provide everything with the question
Answer:
The lengths of all sides of the triangle will be 21 cm, 21 cm, and 21 cm
Step-by-step explanation:
Given that the perimeter of the triangle = 63 cm
And the length of one side = 21 cm
and one of the medians is perpendicular to one of its angle bisectors
Since triangle has 3 sides,
Median = 63 ÷ 3 = 21
Therefore each side length = 21 cm