Standard and Slope Intercept form

Question

A line passes through the points (2,-3) and (1,-1).

Find the equation in. (a) standard form and (b) slope-intercept form

Answer 1

The slope of the line is (y₂ - y₁)/(x₂ - x₁) = [-1 - (-3)]/(1 - 2)

                                                                         = 2/(-1) = -2

 

Use the point-slope form :  y - y₁= m(x - x₁)

 

Equation of line:  y - (-3) = -2(x - 2)

 

                              y + 3 = -2x + 4

 

                                    y = -2x + 1  ←  slope-intercept form

 

                                   2x + y = 1    ←  standard form