[tex]Daca \frac{3x+4y}{2x+y} = \frac{7}{3} , atunci \frac{x}{y} = ?[/tex]

[tex]Daca \frac{6x+4y}{5x+2y} = \frac{3}{2} , atunci \frac{x}{y} = ?[/tex]

[tex]Daca \frac{5x-4y}{2x-y} = \frac{7}{3} , atunci \frac{x}{y} = ?[/tex]



Răspuns :

1. [tex] \frac{3x+4y}{2x+y} = \frac{7}{3} [/tex]
Inmultim pe diagonala si se obtine : 7(2x+y)=3(3x+4y)⇒ 14x+7y=9x+12y⇒14x-9x=12y-7y⇒5x=5y. Impartim toata ecuatia la 5⇒ x=y ⇒ [tex] \frac{x}{y} [/tex]=1

2. [tex] \frac{6x+4y}{5x+2y}= \frac{3}{2} [/tex]
Procedam ca la primul si inmultim pe diagonala :
3(5x+2y)=2(6x+4y) ⇒ 15x+6y=12x+8y ⇒ 15x-12x=8y-6y⇒3x=2y⇒ [tex] \frac{x}{y} = \frac{2}{3} [/tex]

3. [tex] \frac{5x-4y}{2x-y}= \frac{7}{3} [/tex]
Inmultim pe diagonala : 
3(5x-4y)=7(2x-y) ⇒ 15x-12y=14x-7y⇒15x-14x= -7y+12y⇒ x= 5y ⇒ [tex] \frac{x}{y} [/tex]=5