Răspuns :
a+b=521
a:b=5rest 35 => a=5b+35
5b+35+b=521
6b=521-35
6b=486
b=486:6
b=81
a=5x81+35
a=405+35
a=440
verificam: 440+81=521
a:b=5rest 35 => a=5b+35
5b+35+b=521
6b=521-35
6b=486
b=486:6
b=81
a=5x81+35
a=405+35
a=440
verificam: 440+81=521
x+y=521 ; x:y=5rest35 ;x=(5·y)+35 ; (5·y)+35+y=521 ;5·y+y=521-35 ;y=486:6=81 ; x+81=521 ; x=440 ; 440+81=521