so the slope of the other line that is perpendicular is negative and reciprocated.
so when the line passes through the origin that means it is direct variation.
direct variation equation y=kx
which means the y-intercept or b is 0.
the formula is y=mx+b
m= slope.
x,y are coordinates
b is the y-intercept.
so first reform the given equation to the formula i gave to get the slope.
so 2y=-x+8
y=-1/2x+8
-1/2=m=slope.
negative, reciprocal.
2=m=slope of the perpendicular line.
so the ans is y=2x