Răspuns:
[tex]a.a/b=5/7= > a=5b/7\\\\2a-b=24\\\\2*5b/7-b=24\\\\numitor .comun-7\\\\10b-7b=168= > b=168:3= > b=56\\\\a=5*56:7=40\\\\\\\\b.a/b=3/5= > a=3b/5\\\\3a+2b=133\\\\3*3b/5+2b=133\\\\numitor.comun-5\\\\9b+10b=665= > b=665:19= > b=35\\\\a=3*35:5= > a=21[/tex]