Find the equation of the line passing through the points (-2,1) And (2,3).

Question

(-2,1)

(2,3)

 

Answer 1

Slope-intercept form:  y = mx + b

 

Find the slope, m:

m = (y₂ - y₁)/(x₂ - x₁) = (3 - 1)/(2 - (-2)) = 2/4 -->  m = 1/2

 

Find the y-intercept, b, using one of the (x,y) points (either will do):

y = (1/2)x + b

3 = (1/2)(2) + b

3 = 1 + b -->  b = 2

 

This gives the equation:  y = (1/2)x + 2

 

You could also plot the two points and obtain this information from the graph.