The equation Capt Pit Bull stated is exactly the same as mine but uses different terms. I used a constant of energy lose per min so you could get a rate of decent per min.
Putting the weight on the bottom does nothing to affect the solution of the relationship. It gives us an inverse relationship. Accuracy is an issue with expicit solutions not implicit.
Why do you insist on bring L/D none dimensional ratio into it and TAS its not required and adds nothing to the relationship of rate of decent to weight.
People have focused on the mechanics of the the conversion instead of boxing off the system and applying basic physics laws
As I said very very common mistake for engineers early on in their academic education and for some it never does click. Thankfully they make very good accountants