Notam necunoscutele cu : e-elevi. b-baieti f-fete. b+f= e ->b+f=276 f=2*b Acum facem sistem in care vom avea 2 ecuatii si anume ''b+f=276 '' si f=2*b [tex] \left \{ {{b+f=276} \atop {f=2b}} \right. -\ \textgreater \ \left \{ {{b+2b=276} \atop {f=2b}} \right. -\ \textgreater \ \left \{ {{3b=276} \atop {f=2b}} \right. -\ \textgreater \ \left \{ {{b=276:3} \atop {f=2b}} \right. -\ \textgreater \ \left \{ {{b=92} \atop {f=2b}} \right. [/tex] -> [tex] \left \{ {{b=92} \atop {f=2*92}} \right. -\ \textgreater \ \left \{ {{b=92} \atop {f=184}} \right. [/tex] In concluzie sunt 92 de baieti si 184 de fete.
