Find an equation of the line L. L is perpendicular to y=-2x and is passing through points 2,-4

slope of line y= -2x is -2
slope of line L= (-1)reciprocal of slope line y= -2x.
=( -1)(-1/2)
=1/2
since the L passes through (2,-4),
equation of line L: y-(-4)= 1/2(x-2)
2y+8 = x-2
x-2y-10=0
Hence equation of line L is x-2y-10=0