Răspuns:
[tex]a+b+c+d=82\\\\b=a+9= > a=b-9\\\\b=c-9= > c=b+9\\\\d=c+9= > d=b+9+9= > d=b+18\\\\inlocuim .in.prima.relatie\\\\b-9+b+b+9+b+18=82\\\\4b=82-18= > b=64:4= > b=16\\\\a=16-9= > a=7\\\\c=16+9= > c=25\\\\d=16+18= > d=34\\\\verificare:\\\\a+b+c+d=7+16+25+34=82[/tex]
