#123 is a bit more of a 'Formal' typeface, I guess it depend on what you mean by 'formal' specifically, in terms of formal fonts usually it's a serif or calligraphic font or sans serif with space added added to the letters it adds to the simplicity.. Here I added more space to this sans serif font for 'Aprendizaje', and 'inteligente' being the operative word I've presented in a formal calligraphy style font but on a youthful wave line..
I applied the whole loge to the cover of your book 'Aprendizaje Inteligente' to see if in would look ok as the title on the book and
#123 worked the best from about thirty different variations.