Răspuns:
xy=69
Explicație pas cu pas:
Presupunem xy ca avind bara deasupra:
xy0+xy2+xy4=2007+xy
Dar xy0=10×xy+0. Similar, gasim:
(10×xy+0)+(10×xy+2)+(10×xy+4)=2007+xy.
30×xy+6=xy+2007
29×xy=2001
Deci numarul xy=2001/29=69
