If we assume that the square root of two is a rational number, then we can say that the square root of two is A over B... where A and B are whole numbers and B is not zero.
Biren erro karratua zenbaki arrazionala dela onartzen badugu, biren erro karratua A zati B dela esan dezakegu A eta B... zenbaki osoak izanik eta B zeroren ezberdina.