Răspuns :
a-b=20=>a=20+b
b·6=a·3=> b·6=3(20+b)=> 6b=60+3b => 6b-3b=60 => 3b=60 => b=20
a=20+b => a=20+20 => a=40
a+b=40+20=60
2·(a+b)=2·60=120
b·6=a·3=> b·6=3(20+b)=> 6b=60+3b => 6b-3b=60 => 3b=60 => b=20
a=20+b => a=20+20 => a=40
a+b=40+20=60
2·(a+b)=2·60=120
X-y=20=>x=20+y
Y·6=x·3=> y·6=3(20+y)=> 6y=60+3y => 6y-3y=60 => 3y=60 => y=20
a=20+y => x=20+20 => x=40
X+y=40+20=60
2·(x+y)=2·60=120
Sper că te-am ajutat