Answer
$$y = - \frac{1}{2}x + 12$$
Work Step by Step
$$\eqalign{
& y{\text{ - intercept }}\underbrace {\left( {0,12} \right)}_{\left( {0,b} \right)} \cr
& x + 2y = 8 \to \underbrace {y = - \frac{1}{2}x + 4}_{y = mx + b} \cr
& {\text{The line is parallel to the line }}x + 2y = 8,{\text{so they have the same}} \cr
& {\text{slope.}}{\text{. Then }} \cr
& m = - \frac{1}{2}{\text{ and }}y{\text{ - intercept }}\underbrace {\left( {0,12} \right)}_{\left( {0,b} \right)} \cr
& {\text{Use the slope - intercept form of the equation of a line}} \cr
& y = mx + b,{\text{ where }}m = slope,{\text{ and }}\left( {0,b} \right){\text{ is }}y{\text{ - intercept}} \cr
& y = - \frac{1}{2}x + 12 \cr
& \cr
& {\text{Graph}} \cr} $$
