Question

What is an equation of the line that passes through the points (1, -7) and (-4, 8)?

Answer 1

Answer:    y + 7  =  -3 (x - 1)

Step-by-step explanation:

The slope of the line (m) = (y₂ - y₁) ÷ (x₂ - x₁)  

                                       

                                          =  (- 7 - 8) ÷ ( 1 - (- 4))

                                         =    - 15  ÷  5

                                         =  - 3

We can now use the point-slope form to write the equation for this line:

        y - y₁ = m(x - x₁) where (x₁ , y₁) = (1, -7)

             y - (-7) =  -3 ( x  -  1)

              y + 7  =  -3 (x - 1)