Notam cu : b- baieti
a- fete
Ni se da: a + b = 10
a = 1/ 4 * b
Ni se cere: a = ?
Rezolvare: [tex]a~+~b~=~10\\\\
a~=~ \frac{1}{4} ~*~b\\\\
--------------\\\\
\frac{1}{4} ~*~b~+~b~=~10\\\\
ADUCEM~TOTUL~LA~ACELAS~NUMITOR,SI~IN~PARTEA\\
STANGA,~SI~IN~CEA~DREAPTA.\\\\
b~+~4b~=~40~=\ \textgreater \ ~5b~=~40~=\ \textgreater \ ~b~=~40~:~5~=\ \textgreater \ ~b~=~8\\\\
a~+~b~=~10~\ \textless \ =\ \textgreater \ a~+~8~=~10~=\ \textgreater \ ~a~=~10~-~8~=\ \textgreater \ ~a~=~2[/tex]
Numarul fetelor care au plecat in excursie este egal cu 2.
Raspuns: d) 2 fete