A particle is observed to to pass through a distance d horizontally and d/10 vertically from the point of projection. Show that if T= tan (theta) then T satisfies the equation:

75T^2 - 40T + 4 =0

What is confusing me is how to do this without values as I have an equation to form the quadratic equation:

x tan(theta) - x^2(g/2u^2)sec^2(theta)