What is the equation of the line

Question

what is the equation of the line through x-intercept,-1, and y-intercept ,2 

Answer 1

What is the equation of the line through x-intercept,-1, and y-intercept ,2?

 

The x-intercept is the point (-1,0) and the y-intercept is the point (0,2).

 

The equation of a line is:

 

y = mx + b

 

Where m = the slope of the line and b is the y-intercept.  We already know the y-intercept, b=2. So all we need is the slope, m.  The slope is defined as the change in y over the change in x between any two points (x₁,y₁) and (x₂,y₂) on the line:

 

         (y₂ - y₁)

m =  ------------

         (x₂ - x₁)

 

We have two points: the x-intercept (-1,0) and the y-intercept (0,2).  Hence:

 

 

        (y₂ - y₁)       (2 - 0)        2
m =  ---------- =   --------   =  ---  = 2
        (x₂ - x₁)     (0 - (-1))      1

 

Therefore the equation of the line is:

 

y = 2x + 2