Răspuns :
Notam cele 3 numere cu a, b si c.
a+b+c=890
a+b=403
--------------(-) (Le scadem)
c=487
Inlocuim in a treia relatie: b+c=565⇔b+487=565⇔b=78
a+b+c=890⇔a+78+487=890⇔a=890-78-487⇔a=325
Deci a=325, b=78 si c=487
a+b+c=890
a+b=403
--------------(-) (Le scadem)
c=487
Inlocuim in a treia relatie: b+c=565⇔b+487=565⇔b=78
a+b+c=890⇔a+78+487=890⇔a=890-78-487⇔a=325
Deci a=325, b=78 si c=487