## 1. WRITING THE EQUATIONS OF THE LINE

### 1.1. linear equations can be written in 3 forms

1.1.1. Standard Form : Ax + By = C

1.1.2. General Form : Ax + By + C = 0

1.1.3. Slope - Intercept Form : y = mx + b

## 2. GRAPHING LINEAR EQUATIONS

### 2.1. we can graph linear equations using

2.1.1. x - and y intercepts

2.1.2. a point and slope of the line

2.1.3. two points of the line

## 3. PARALLEL AND PERPENDICULAR LINES

### 3.1. Two lines are parallel if they have the same slope and different y - intercepts

3.1.1. slope of L1 = slope L2

### 3.2. Two lines are perpendicular if their slopes are opposite reciprocals

3.2.1. the product of their slopes is always equal to -1