the equation of the line is,
y = 2x + 5
the slope of the line is m = 2
the slope of the line perpendicular to y = 2x + 5 is ,
m = -1/2
it is passing through (-2,8)
so the equation of the line is
[tex]y-8=(-\frac{1}{2})(x-(-2))[/tex][tex]\begin{gathered} y-8=-\frac{1}{2}x-1 \\ y=-\frac{1}{2}x+7 \end{gathered}[/tex]thus the equation of the line is,
y = -1/2 x + 7