On parental support | Leonhard Euler (1707-1783)

The excerpt comes from an Introduction to the Elements of Algebra written by Euler (1707 -1783) when he already blind. The book of unsurpassable clarity it can be used as an introduction to algebra nowadays just as it was more than two centuries ago. For an extended read exploring the book I would direct you to “A tale of two curricula: Euler's algebra text book” by Chris Sangwin