Răspuns :
a+b=20;
a=2b ;
Inseamna ca 2b+b=20=> 3b=20:3=> a=6,67 ; b=20-6,67=13,33
a+b=20; a=2b --> 2b+b=20 --> 3b=20 --> b=20/3, iar a=2*20/3=40/3;
verificare: 40/3 + 20/3=60/3=20
:D
verificare: 40/3 + 20/3=60/3=20
:D