Originally Posted by
+TSRA
Remember that the 1 in 60 rule is solving for a triangle. Whether you do it algebraically or written out as you did, you're doing the same thing. They're not two different techniques, they're two different presentation formats of the same technique.
They are different. One is a gross simplification, taking into account the fact that +\-50fpm is as good as you’ll get for flying ability. Pointless getting anything more accurate as an answer.
The whole syllabus is based on these approximations, as it should be.