Write an equation in point-slope form, y – y1 = m(x – x1), of the line through points (4, –4) and (1, 2). Use (4, –4) as the point (x1, y1).

Question

 need help. i dont understand

Answer 1

First we need to find the slope m using the two points.

 

m = (y₂ - y₁) / (x₂ - x₁)

m = ( 2 - (-4)) / (1 - 4)

m = (2 + 4) / (1-4)

m = 6/(-3)

m = -2

 

Now we can use the point-slope form to find the line.

 

y - y₁ = m(x - x₁)

 

y - (-4) = -2(x - 4)

 

y + 4 = -2x + 8

y = -2x + 4