Fórmula suma progresión aritmética n primeros términos

How to obtain the sum of the first n terms of an arithmetic progression. You must add the sum of the first n terms written in ascending order to the sum of the first n terms written in descending order. Keeping in mind that the sum of equidistant terms remains constant in an arithmetic progression, you arrive at the desired result, which is the sum formula. #math #mathwithjuan