Răspuns:
3a+2b+17=36
3a+2b=36-17
3a+2b=19
6a+4b |:2 =3a+2b=19
==> 6a+4b= (3a+2b)×2
6a+4b=19×2
6a+4b=38
==> 6a+4b+47=38+47=85
Răspuns final: 85