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Algebra

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Sure! Here’s a quick rundown of some key algebra concepts and formulas.

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### Basic Concepts

1. **Variables and Constants**


- **Variable**: A symbol (usually a letter) that represents an unknown value (e.g., \( x \), \( y \)).
- **Constant**: A fixed value (e.g., 5, -3).

2. **Expressions and Equations**


- **Expression**: A combination of variables, constants, and operators (e.g., \( 3x + 4 \)).
- **Equation**: A statement that two expressions are equal (e.g., \( 2x + 3 = 7 \)).

3. **Terms and Coefficients**


- **Term**: A single mathematical expression (e.g., \( 3x \), \( -2 \)).
- **Coefficient**: The number in front of a variable (e.g., in \( 5x \), 5 is the coefficient).

### Operations with Algebraic Expressions

1. **Addition and Subtraction**


- Combine like terms: \( 3x + 4x = 7x \) and \( 5 - 2 = 3 \).

2. **Multiplication**
- Use distributive property: \( a(b + c) = ab + ac \).
- Example: \( 2(x + 3) = 2x + 6 \).

3. **Division**
- Divide each term in the numerator by the denominator: \( \frac{4x + 8}{4} = x + 2 \).

### Solving Equations

1. **One-Step Equations**
- Solve for \( x \): \( x + 5 = 12 \) → \( x = 12 - 5 \) → \( x = 7 \).

2. **Two-Step Equations**
- Solve for \( x \): \( 2x + 3 = 11 \)
- Subtract 3 from both sides: \( 2x = 8 \)
- Divide by 2: \( x = 4 \)

3. **Multi-Step Equations**
- Example: \( 3(x - 2) + 4 = 16 \)
- Distribute: \( 3x - 6 + 4 = 16 \)
- Combine like terms: \( 3x - 2 = 16 \)
- Solve for \( x \): \( 3x = 18 \) → \( x = 6 \)
### Factoring

1. **Greatest Common Factor (GCF)**


- Factor out the largest common factor from each term: \( 6x + 9 = 3(2x + 3) \).

2. **Quadratic Expressions**
- **Factoring by Grouping**: \( x^2 + 5x + 6 \) can be factored as \( (x + 2)(x + 3) \).
- **Difference of Squares**: \( a^2 - b^2 = (a + b)(a - b) \).

### Functions and Graphs

1. **Linear Functions**
- **Slope-Intercept Form**: \( y = mx + b \) where \( m \) is the slope and \( b \) is the
y-intercept.
- Example: For \( y = 2x + 1 \), slope \( m = 2 \) and y-intercept \( b = 1 \).

2. **Quadratic Functions**
- **Standard Form**: \( y = ax^2 + bx + c \)
- The graph is a parabola. The vertex can be found using \( x = -\frac{b}{2a} \).

### Systems of Equations

1. **Substitution Method**
- Solve one equation for one variable, then substitute into the other equation.

2. **Elimination Method**
- Add or subtract equations to eliminate one variable, then solve for the remaining variable.

### Inequalities

1. **Solving Inequalities**
- Solve similarly to equations but remember to reverse the inequality sign when multiplying or
dividing by a negative number.

2. **Graphing Inequalities**
- Represent solutions on a number line or coordinate plane, shading the appropriate region.

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