notezi astfel:
n:11=a rest b si n:13=b rest a ; a<13 si b<11
n=11a+b si n=13b+a
n=11a+b=13b+a=>11a-a=13b-b=>10a=12b=>5a=6b=>a=[tex] \frac{6b}{5} [/tex]
pt ca a sa fie nr natural trebuie ca [tex] \frac{6b}{5} [/tex] sa fie numar natural=>
b={5;10;15......} dar b< 11=> b={5;10}=>
b=5=>a=[tex] \frac{6x5}{5} [/tex]=6(<13)
b=10=>a=[tex] \frac{6x10}{5} [/tex]=12 (<13)
=>perechile sunt: (5 si 6);(10 si 12)
coronita?