Least Square in Excel: Finding the coefficients / Cálculo de los coeficientes

We call Chemometrics the statistics, matrix algebra,..., applied to chemical analysis.
Same for Economics, I have found at the Public Library of my Village an interesting Book:
"Econometría Básica - Técnicas y herramientas" - Cesar Perez (Pearson).
I develop here in Excel one of the exercices of the book:
The result match the solution......GOOD.