k = [tex]\frac{2m-x}{x}[/tex]
k = [tex]\frac{2m}{x}[/tex] - [tex]\frac{x}{x}[/tex]
k = [tex]\frac{2m}{x}[/tex] - 1
kx = 2m - x
kx+x = 2m
(k + 1) x = 2m
x = [tex]\frac{2m}{k+1}[/tex]
