Se considera proporția
Ex3

Răspuns:
[tex] \frac{7x + 3y}{5x + 6y} = \frac{4}{5} \\ 35x + 15y = 20x + 24y \\ 15x = 9y \\ 5x = 3y[/tex]
Răspuns:
5(7x+3y)=4(5x+6y)
35x+15y=20x+24y
35x-20x=24y-15y
15x=9y |÷3
5x=3y