c-varsta Corinei
r- varsta Ralucai
r+c=26==> c=26-r
c^2-r^2=52
(26-r)^2-r^2=52
(26^2-2•26•r+r^2)-r^2=52
676-52r+r^2-r^2=52
676-52r=52
-52r=52-676
-52r=-624
r=-624:(-52)
r= 12
c=26-r
c=26-12
c=14
c-r=14-12=2 ani
verificare:
c+r=26
14+12=26
c^2-r^2=52
14^2-12^2=52
196-144=52