Intermediate Algebra (12th Edition)

$y=-x-2$
The given graph of a line passes through the points $( 0,-2 )$ and $( -3,1 ).$ Using $y-y_1=\dfrac{y_1-y_2}{x_1-x_2}(x-x_1)$ or the two-point form of linear equations, then the equation of the line is \begin{array}{l}\require{cancel} y-(-2)=\dfrac{-2-1}{0-(-3)}(x-0) \\\\ y+2=\dfrac{-2-1}{0+3}(x) \\\\ y+2=\dfrac{-3}{3}x \\\\ y+2=-1x \\\\ y=-x-2 .\end{array}