[tex]x=\text{Cantitatea de smantana de 20 Lei/ Kg } \\ y=\text{Cantitatea de smantana de 12 Lei/ Kg } \\20x+12y=14(x+y) \\ 20x+12y=14x+14y \\ 20x-14x+12x-14y=0 \\ 6x-2y=0\;\;\;\;\;\;\; | :y \;\;\;\text{(impartire fortata)} \\\\ 6* \frac{x}{y} -2* \frac{y}{y} =0 \\\\ 6* \frac{x}{y} -2=0 \\\\ 6* \frac{x}{y} =2 \\\\ \frac{x}{y}= \frac{2}{6}= \boxed{\frac{1}{3}} [/tex]
=> Vindetot a o parte smantana de 20 lei/kg cu 3 parti smantana de 12 lei/kg
