Slope-Intercept equation I need help with

Question

Write the equation of the line that passes through each pair of points in slope-intercept form. (6,5), (-9,-20)

Answer 1

Hi Sherry,

 

The basic form of an equation of a line in the slope intercept form is y = mx + b

However, given two points, we have to begin with the point slope form which is y-y₁ = m(x-x₁)

 

From the points given we can calculate the slope, m

m = y₂-y₁

       ------

       x₂-x₁

 

m = (-20-5)/(-9-6) = -25/-15 = 5/3

 

and

 

y-5 = (5/3)(x-6)  <--- point slope form

y-5 = (5/3)x - 10

y = (5/3)x - 5     <---- slope intercept form