Download Write the equation of a line

Write the equation of a line
Y-intercept
(0, b)
Slope-intercept
y = mx + b
Replace m and b into the
equation
Slope
m
Point
Point
(x1 , y1)
(x2 , y2)
Point-slope
y  y1  m  x  x1 
Replace m and (x1 , y1 ) into
the equation
1. Find the slope
y  y1
m 2
x 2  x1
2. Pick a point as (x1 , y1 )
3. use Point-slope form
y  y1  m  x  x1 
If two lines are parallel to each other, their slopes are the same.
If two lines are perpendicular to each other, their slopes are opposite reciprocals.