Table of Contents
Definition
General Form of the equation of a straight line is:
Ax + By + C = 0
Note:
A or B can’t be zero at the same time.
(if A = 0 then B ≠ 0, vice versa)
The General Form is not always the most useful form, and you may prefer to use:
Slope-Intercept Form Of The Equation Of a Line
Slope-Intercept Form of the equation of a straight line is:
y = mx + b
Point-Slope Form of the equation of a line
Point-Slope Form of the equation of a straight line is:
y − y1 = m(x − x1)
Example
Convert 6x − 3y − 9 = 0 to Slope-Intercept Form
We are heading for:
y = mx + b
Start with:
6x − 3y − 9 = 0
Move all except y to the right:
−3y = −6x + 9
Divide all by (−3):
y = 2x − 3
And we got m = 2 and b = −3
Well done!