y' = (x +y)/(x-y)
In my Finnish math book they classify this as a differential equation which is "reducible to equal degree". They present a way of solving this type of equation, but the explanation is really bad. I've been trying to find more information, but I just can't figure out what these are called in English. Even Wolfram Alpha doesn't know (it suggests a more general classification, "first-order nonlinear differential equation").
Does anyone know of a name for this type of differential equation? Can you direct me to a book, website or video which explains how to solve these? I'm really stuck. Any material at all would be appreciated.