1. 2-4B Writing equations for Parallel & Perpendicular lines
Algebra 2

2. Write equations of parallel or perpendicular lines
1.) Identify slope of given equation
2.) Identify slope to use for Parallel or Perpendicular Line
A.) Parallel lines – have the SAME slope
B.) Perpendicular lines – have OPPOSITE & RECIPROCAL slope
3.) Substitute point and slope from step #2 into either point-slope form or slope-intercept form twice.

3. Example 1
Ex. 1 Write an equation of the line that passes through ( -2, 1) and is parallel to the line y = -3x + 4

4. Example 2
Ex. 2 Write an equation of the line that passes through ( 3, -1) and is parallel to the line y = 4x + 5

5. Example 3
The number of U.S. cell phone subscribers increased from 16 million in to 44 million to Find the average rate of change and use it to estimate the number of subscribers in 1997.