As a person who often struggled in math for perhaps many reasons, this was a common issue for me. First you define things, then you use them. No other rule ma

As a person who often struggled in math for perhaps many reasons, this was a common issue for me. First you define things, then you use them. No other rule makes sense generally, and I challenge anyone to prove me wrong. Now is a simple set like { 2x : x ∈ ℝ } going to confuse me, probably not... but when variables are just thrown around all willy nilly, I get confused pretty quick.