How do you represent a straight line in coordinate geometry?

A straight line represents a linear equation on an X-Y plane. The equation of a straight line can be written in the following three forms:

1. The slope intercept form: The equation of a line with slope  is , where  is equal to the "y" intercept. This is the most commonly used equation format.  Since the "y" intercept of a line passing through the origin is 0, the equation of a line with slope  passing through the origin is  
   
   
2. The point slope form: The equation of a line passing through   with slope  can be written  
   
   
3. Two Points form: The equation of a line passing through points   can be written as 
   
   

Example:

What is the equation of a line with a slope   passing through point ?

A) 

B) 

C) 

D) 

E) 

Solution:

The equation of a line passing through   and with a slope is given by 

Here, 

Substituting the values in the equation,

we get, 

B is the correct answer.